# Let's Talk about making Naturally Aspirated Horsepower



## Jettaboy1884 (Jan 20, 2004)

*_Edited for the new Forum_*

Hello,
The ultimate goal is to make this thread a source of information on how to extract power from a naturally aspirated engine.
A little about myself: I read a LOT of information online. Over time I have gathered a bunch of articles on how to tune engines. I know that there is a lot to learn, and that tuning engines is a very complex science. I have only begun to learn about Resonance tuning the intake ports, and exhaust system tuning. Frankly, this stuff is amazing and I want to learn more.

Here are the articles that I have gathered so-far. It is important to mention that I have not written any of these. The Authors' information can be found in each respective article:

Excellent article on Exhaust tuning, easy to understand:
http://www.superchevy.com/tech....html

Good article on engine terminology, and different layouts of various engine components. Good pictures:
http://www.carbibles.com/fuel_engine_bible.html

Alternative Intake Manifold discussion:
http://www.mne.psu.edu/me415/S....html

Somender Singh's Groove theory/discussion:
http://somender-singh.com/content/view/7/49

Intake manifold design and tuning from Grape Ape Racing. (Check out their other technical articles)
http://www.grapeaperacing.com/...s.pdf

This is all I have for now. I have some more articles on my home PC. I'll add them later.


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## ny_fam (Apr 3, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

I see the article on the groove theory, and I have some first hand experience with it so I have a few comments.
This groove technique is specifically for engines with squish zone clearance of about .070". These 8v valve VW engines have a .140" squish zone on one side(spark plug side) and .070" on the other side of the chamber. Not good for good mixture and not really good to take advantage of the grooves.
Since the groove techniques goal is to increase the mixture and initial speed of flame propagation. Its worth noting that there are better ways to accomplish this. Its a proven fact that the max squish zone clearance for good mixture and flame front speed is .050" So a custom set of pistons are in order. Of course less is clearance is better up to a point.
Thats not clear is how much better if at all are the grooves on the vw 8v engine of no grooves. A back to back test would be needed. My test wasn't really valid due to the other changes I did to the engine at the same time.
I don't think there is any comparison between grooves and .050" or less clearance - hands down goes to proper clearance.
ny_fam


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ny_fam)*


_Quote, originally posted by *ny_fam* »_I see the article on the groove theory, and I have some first hand experience with it so I have a few comments.


Thanks.
So, would I be correct to assume that if I am going to put a groove in a 8v head, I should only put one (or more) on the side opposite the spark plug?

Heck, has anyone ever put a groove in the piston? I would think that if you matched it with the groove in the head, it could have more of an effect.

Another question:
On a modern EFI engine, is it better to polish the intake ports mirror smooth, or leave "dimples" to encourage a layer of turbulent air along the port walls?


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Generally intake manifolds can be smooth, but once in the head (with fuel) they should be left slightly rough. 
+1 on the squish clearance, though the Volvo 8v guys have been having good luck with the groove on similar 2 valve heads when used with very tight squish at the same time.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_Generally intake manifolds can be smooth, but once in the head (with fuel) they should be left slightly rough.

And why is this? I know the traditional answer is that the rough surface helps keep a turbulent layer of air along the port walls, which in turn helps keep the fuel from "falling out" and running along the walls.
I have a couple of reasons why I don't take this for granted:

1. I think that on older carbed motors, this is much more applicable. The carb doesn't atomize the fuel as well as a modern fuel injector. On EFI motors the fuel is sprayed directly at the intake valve immediately before it opens (correct?) So, being that the fuel is atomized much more efficiently, and it is only suspended in the intake charge for a short period of time, do the port walls _really need_ to be rough?

2. I don't know if I really believe that there are small eddies of air present along a rough port wall. Example: A golf ball has dimples which create eddies/air bubbles along the surface, which in-turn allow the golf ball to move thru the air with less resistance (and more stability?) However, the air flowing thru an intake port actually has to stop-and-go thousands of times per minute. All this stop-and-go causes pressure pulses to travel up and down the intake tract. So, I wonder if the constant stop-and-go, combined with the pressure waves allows for these eddies to stay intact?

I think the only real way to prove or disprove this would be to do a back to back test on a cylinder head with smooth ports, and one with dimples in the port wall...
Any thoughts?


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

I'm not sure if I 100% buy it either, but doing an 80 grit job is easier then polish so call me lazy







Back to back testing is almost impossible and I'm betting that the differences that you would see are in the noise of the test itself.


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## ny_fam (Apr 3, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
And why is this? I know the traditional answer is that the rough surface helps keep a turbulent layer of air along the port walls, which in turn helps keep the fuel from "falling out" and running along the walls.


Addition to this is a rough surface helps the fuel that has dropped out to re- atomize and not puddle

_Quote, originally posted by *Jettaboy1884* »_
I have a couple of reasons why I don't take this for granted:
1. I think that on older carbed motors, this is much more applicable. The carb doesn't atomize the fuel as well as a modern fuel injector. On EFI motors the fuel is sprayed directly at the intake valve immediately before it opens (correct?) So, being that the fuel is atomized much more efficiently, and it is only suspended in the intake charge for a short period of time, do the port walls _really need_ to be rough?


From the pro porters they say it really doesn't matter. Like .o1% difference. Its true modern injectors atomize fuel better than carbs but our 8v's aren't running modern FI systems. Take the fact that CIS stands for Continuous Injection System. All 4 injectors are spraying at the same time. So only 1 at a time are really spraying into a valve that is opening. The rest are spraying at a closed valve. Again the real mixture comes in at TDC during squelch.
Polishing the intake tract is a waste of time. Mostly its very time consuming to do a good porting job. Then to spend extra time for no additional measurable value is just silly.


_Quote, originally posted by *Jettaboy1884* »_
2. I don't know if I really believe that there are small eddies of air present along a rough port wall. Example: A golf ball has dimples which create eddies/air bubbles along the surface, which in-turn allow the golf ball to move thru the air with less resistance (and more stability?) However, the air flowing thru an intake port actually has to stop-and-go thousands of times per minute. All this stop-and-go causes pressure pulses to travel up and down the intake tract. So, I wonder if the constant stop-and-go, combined with the pressure waves allows for these eddies to stay intact?


Those pulses in the intake tract are the only reason why FI systems are capable of being %100 volumetric effieient. Carb setups can't

_Quote »_
I think the only real way to prove or disprove this would be to do a back to back test on a cylinder head with smooth ports, and one with dimples in the port wall...
Any thoughts?

Agreed but would have to be CNC done to ensure perfection in the test.
I've seen test that indicate a cross hatched surfaced in a long tube help increase air speed and volume. But the tests run were in isolation and not part of a system like the running IC engine.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ny_fam)*


_Quote, originally posted by *ny_fam* »_
Again the real mixture comes in at TDC during squelch.


What's Squelch?

_Quote, originally posted by *ny_fam* »_Those pulses in the intake tract are the only reason why FI systems are capable of being %100 volumetric effieient. Carb setups can't


From what I've read about intake and exhaust tuning (in the articles above) it is possible to get an NA motor to even more than 100% VE.
On a similar note: I've been looking into SHO engines a bit more, as I plan to have one someday. I was thiking about the effects of the secondary throttlebodies when they open up the shorter runners. I am wondering how they effect the intake pulses, considering that the cylinder is drawing air from two valves that are each sharing two different runner lengths.
I wonder if the SHO intake has tuned runner lengths, or if the Yamaha engineers just felt that long primaries and short secondaries were good enough.


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Hi there I would like to jump in here with both feet.
There are several important keys to making big power with a naturally aspirated engine.
Getting air and fuel in is one thing we have touched on at this point.
All of us talking about this subject should know that there are several more factors that we need to look at.
I think the key to big NA horsepower and unfortunately the reason you don't see these types of engines in street cars is RPM.
The higher the RPM the higher the HP as long as the engine can support it.
What this means is that everything must be built to accommodate high RPM use. 
Now I am not just talking about the strength of the engine to handle High RPM use but also making the engine more efficient at high RPM.
One thing to look at to achieve this high rpm efficiency is the bore stroke ratio.
If you look at most of the great engines throughout history, most of them are what is called OVERSQUARE, meaning that their bore is bigger than it's stroke.
The 1.8 liter 8 valve VW engine is far from oversquare. 
But like most engines this can be changed.
It might not be cheap but it is do-able.
The goal is to keep the displacement the same or maybe a little bigger but make the bore bigger than the stroke.
I am not sure what kind of bore the stock VW blocks can handle but I assure you they can go bigger.
With the crank there are several options, all of which have pros and cons and many of which may not be possible with your particular engine.
Option one would be to have the crank offset ground to shorten the stroke.
Pros: It’s cheap and it’s cheap.
Cons: It’s still a stock crank and unless it is a factory-forged piece it can only handle so many RPM. Also the reduction in stroke is minimal but it could help.
Option two would be to find a good stock crank with a shorter stroke that will bolt in place.
Pros: again it is cheap and if it is a forged unit it should be plenty strong
Cons: I am not real sure about VW but most companies don’t build stock forged cranks and if they do they might not have so many engines with different displacements to pick from that will share cranks.
What I would consider the last option is an aftermarket or custom billet crank.
Pros: They are super strong and, theoretically, you can get any stroke you might need.
Cons: $$$The Price$$$
you will have to do your research at this stage and pick the right pistons and crank to get the right displacement but the point here is to shorten the stroke then increase the bore to make up for the loss in in displacement. 
I guess now would be the time to explain why it is better to have a short stroke and a bigger bore.
The real advantage is the reduced piston speed due to the shorter stroke.
The piston has to travel less distance in the same amount of time at any given RPM when compared to an engine with a long stroke.
Since speed is distance divided by time we can see that the piston will be moving slower.
This aids in cylinder filling, reduces friction and reduces the stresses on the connecting rod.
Also a shorter stroke reduces the angle of the connecting rod, which reduces pressure on the cylinder wall and reduces friction.
All of this adds up to a engine that can rev higher before it will reach the stress levels that an engine with a greater stoke will reach.
Why am I so focused on RPM?
The answer is simply because the formula for horsepower is as follows.
HP= rpm x T(torque)/5252 (constant)
If all else is the same and you increase the RPM the HP will rise.
Of course some of you are probably saying “ Big deal, if you increase the torque in the formula the HP will also go up”.
While this is true I can tell you that it will be a whole lot easier to raise the RPM by 1000 than it will be to increase the torque by 1000 or even 100 for that matter.
Some may say that the decreased stroke will hurt low rpm power and they would not be wrong.
But, it will be up to you to decide if your car is light enough that it can sacrifice low rpm power to gain a substantial amount on the top end. 
Lets see what else can we do?
The next big thing would be to bump the compression ratio as high as you are comfortable with.
If this is a street engine, then you have to consider the fact that you will probably need to run on pump gas so the compression should be lower.
But if you plan on only running race gas, methanol or ethanol then you can go a lot higher with the comp ratio.
Now I could throw out a bunch of numbers and math and formulas that prove everything I am saying but I am too lazy and anyone can do the research and come to the same conclusions that I have or develope their own so I won't bother.
Now with a good base we can move on to cylinder head, intake and exhaust flow.
Unfortunately the theory for building these is not as straight forward as building the bottom end.
You have to take into consideration the volume of air needed to feed the engine, the volume of the intake plenum, the runner length and the correct exhaust diameter and lengths which are discussed in detail in one of the articles above.
It has been said a hundred times that these sorts of things are a “Black Art” and for the most part that is true but if you have the time, money and a flow-bench these can be narrowed down to something that is suitable for a high revving engine.
There are a couple more “rules of thumb… thumbs?” that will help you along. 
The exhaust is explained pretty thoroughly in the article above so I won’t get into that. 
But I will give you my thoughts on an intake.
For this type of high RPM use I would suggest not running an intake so to speak.
ITBs of the appropriate size are perfect for this type of engine.
By taking the plenum out of the equation this leave only the runner for tuning.
I would start out a little long and cut back to see what happens. 
For my first and maybe my only “rule of thumb”, generally high rpm engines like shorter runners.
Just how short or how long will be left for the dyno to decide.
Sorry there is no way around it.
You cannot build an efficient high HP NA engine without something to tell you how your tuning is going.
A dyno and a flow bench will be your best friend.
Of course you will have to be able to tune all of this.
There is little doubt in my mind that stand alone electronic fuel injection is the only choice to maximize the efficiency and therefore total output of the engine.
One more thing that I think is seriously overlooked is injector placement.
It has been proven that injectors closer to the intake valve is good for low rpm power and injectors placed further out in the intake, Sometimes outside of the throttle body opening, is better for high rpm power.
So why not do both, which is what some motorcycle manufactures are now doing.
This is generally very possible with most aftermarket EFI systems.
I know I left some things out like camshaft selection cylinder head porting and I am sure there are others but most of this stuff will be left up to what is available for your particular engine or what you are willing to pay for custom parts.
Through all of this some of these things may net you greater gains than others but when building a naturally aspirated engine ever little bit helps.
So make of this what you will and feel free to ask me any questions that you can think of.




_Modified by vwhammer1 at 3:53 PM 12-21-2008_


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## rivethead (Nov 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

Oversquare--square - Depends on the motor and the head design/flow at what bore size for the flow with which valves. Example - GM Ecotec in Drag Race trim runs an almost square configuration (86mm by 85mm) with over 1100 HP at the crank.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_Hi there I would like to jump in here with both feet.
.
.
.
So make of this what you will and feel free to ask me any questions that you can think of.


That was great! Thanks a million for taking the time to make that writeup.


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (rivethead)*


_Quote, originally posted by *rivethead* »_Oversquare--square - Depends on the motor and the head design/flow at what bore size for the flow with which valves. Example - GM Ecotec in Drag Race trim runs an almost square configuration (86mm by 85mm) with over 1100 HP at the crank. 

I am definitely not saying that you can't rev a square or even undersquare engine design.
If you build it strong enough it can rev very well.
My point was to maximize the efficiency of the engine design to make it a little less stressful on the parts at high RPM which is where you will need to be to make power without the aid of a turbo.

Also the almost 3.4 inch stroke you listed for the ecotech is still pretty small compared to many engines. 
I also hate to point out that the engine you describe is still an oversquare design and I am sure that didn't happen by accident.


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## kimosullivan (Aug 12, 2002)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_From what I've read about intake and exhaust tuning (in the articles above) it is possible to get an NA motor to even more than 100% VE.

Jaguar was getting up to 125% VE (like 3.5 psi boost) on it's V12 back in the day. This was around 3-4k RPM. The whole intake was tuned to optimize this. The engine used 4 triple throat Webber carburettors with sliding plate throttles instead of butterflies. For a reference, check out _Scientific Design of Intake and Exhaust Systems_, available from Bentley Publishing. With new intake designs and variable length runners, the benefits of a tuned intake can be optimized across a wider RPM range. IIRC, the VW Lupo uses this trick.


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
I think the key to big NA horsepower and unfortunately the reason you don't see these types of engines in street cars is RPM.
The higher the RPM the higher the HP as long as the engine can support it.
What this means is that everything must be built to accommodate high RPM use. 
Now I am not just talking about the strength of the engine to handle High RPM use but also making the engine more efficient at high RPM.
One thing to look at to achieve this high rpm efficiency is the bore stroke ratio.
If you look at most of the great engines throughout history, most of them are what is called OVERSQUARE, meaning that their bore is bigger than it's stroke.
The 1.8 liter 8 valve VW engine is far from oversquare. 
But like most engines this can be changed.


http://****************.com/smile/emthup.gif Thank you, sir!
One of my future projects is to play around with different VW blocks, pistons, and rod ratios to try out an engine with more of an emphasis on revs and horsepower as opposed to typical VW torque! http://****************.com/smile/emthup.gif


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

I think the MKIs are wide open for this type of engine design.
They are just about as small and light as normal cars get.
And when your car only weighs 1800-2000 pounds who needs 300 ft-lbs of torque at 2000 rpm anyway.
This has been the theory for my V8 rabbit all along.
I figured since I am putting a V8 in it anyway I can give up some low end to try and squeeze a little more peak HP.
The turbo engine that will eventually go in it will be a big bore, short stroke 3.8 liter V8 based off of the early 4.2 Audi V8.
I am shooting for a 9000 to 9500 rpm red-line and 1000 hp
However it will have a pair of turbos.
I will not stop with this engine until I either reach 1000 Hp or it explodes and then I will build another and start over just to prove my point.
As far as I know, no one has made 1000 HP with one of these engines and I strongly believe that it's undersquare design is one of the primary reasons.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_
One of my future projects is to play around with different VW blocks, pistons, and rod ratios to try out an engine with more of an emphasis on revs and horsepower as opposed to typical VW torque! http://****************.com/smile/emthup.gif 

I know exactly what you're talking about. I believe that the 1.6L is the best revving 8v motor from VW. IIRC, it has a shorter stroke crankshaft than the others, which allows it to rev higher. I've been wondering lately if it would be possible to stick a 1.6 crank and rods in an ABA block, and use the ABA pistons. According to VWfixx's spec sheet, the ABA has an 82.5mm bore. I can't seem to find the stroke of a 1.6L crank to compare.

_Quote, originally posted by *vwhammer1* »_I am shooting for a 9000 to 9500 rpm red-line and 1000 hp
However it will have a pair of turbos.
I will not stop with this engine until I either reach 1000 Hp or it explodes and then I will build another and start over just to prove my point.


I've been watching your thread. Keep up the good work http://****************.com/smile/emthup.gif 
On the other hand, you can't deny that your engine goal would be a lot more fun if you went NA. A 3.8L V8 at 9500 would sound amazing without FI. Although, reaching that 1000 hp mark would be a lot harder...








Mike.


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

The 1.6 shares main size with the bigger motors, but the rod journal diameter is quite a bit smaller. I also think it has a different crank snout on the pulley side. 
There's some decent info on the smaller engines in the Robert Collins (Drake) archives on Jan's VW page (for those that have been around before Vortex you know what I'm talking about!).


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## ny_fam (Apr 3, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

One of the big factors for high revving mk1 8v's is a very good balance of rotating parts.
The 1.5 is known to rev past 9k rpms in race trim.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ny_fam)*

I remember reading on here that the 1.5L cranks are not forged, and although durable are not as ideal as a 1.6L crank. Are the 1.6L cranks forged?
Do you happen to know the specs of them?


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ny_fam)*

I sincerely think that the cylinder head could be an issue if you are trying to build a high revving engine using the 8V head.
You will really have to open it up and run the biggest valves you can along with a monster cam.
I would hate for you to do all that reving only to be limited by the head flow.
I know we all want to prove that the 8v can make power but it would be a better use of the bottom end of this theoretical engine if a 16v head was used.
I know I am comparing apples to oranges here but I suppose if a Nascar engine can make 750-800 hp using a 2 valve per cylinder engine then maybe an 8v head might work on this engine if it is really reworked.
But look at the amount of modifications and cash that goes into the heads on a Nascar engine.
On another note the smaller rod journal that someone mentioned above has its benefits.
I know the bearing is almost motionless and the crank spins inside it but it is easier to picture if you look at it the other way around.
If the crank is motionless and the rod is whipping around the journal the bearing speed will be less on the smaller journal.
I know that sounds strange and I didn't believe it the first time I heard it either but, if you pick any single point on the bearing surface, that point has to cover less distance in the same amount of time as the big journal would have. (RPM) 
This results in less turbulence in the oil, less friction, and more consistent oiling at any rpm, which could (no, will) be helpful at high rpm. 
Nascar has been using this philosophy for years on the mains and rod journals.
If you were to crack one open you would see bearing sizes more like something you would see in your average Honda or Volkswagen if you prefer.


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## ABF Jeff (Nov 16, 2005)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

I've heard a lot about the 1.7L's ability to rev... the engine I pulled out of my rabbit to put the turbo 16V in was a 1.7L with a built BV JH head modded to fit with a copper head gasket. I revved that engine past 7K and it kept making power.
I think I'm going to explore it a little more...


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_I sincerely think that the cylinder head could be an issue if you are trying to build a high revving engine using the 8V head.
You will really have to open it up and run the biggest valves you can along with a monster cam..
 
http://****************.com/smile/emthup.gif 
This is good info. FINALLY, someone who see's this the same way that I do. Gotta spend your big $$ on the head, folks! You don't know how many times I see people throw boost, $$$, etc, at an engine, and pay NO attention to the head!!

_Quote, originally posted by *vwhammer1* »_I know we all want to prove that the 8v can make power but it would be a better use of the bottom end of this theoretical engine if a 16v head was used.

I know, I know.... but I for one, would like to explore the upper limit of 8v's








The stroke of the VW 1.6l is 86.4 BTW http://****************.com/smile/emthup.gif


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

What if we use thye Diesel crank? Plenty of abuse absortion there!


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ABF Jeff)*

Here is a chart I found that I believe covers all of the bore and stoke specs of the engines we are talking about.
http://www.vintagewatercooleds...s.htm
If this info is correct the 1.5 has the smallest stroke at 73.4mm.
This is followed by the 1.6 at 80mm
Then they are all the same 86.4mm until you get to the 2.0 aba which is 92.78mm
Let's just say we wanted a 1.8 liter engine 
You would probably have to use the 1.6 crank because with the 1.5 crank the bore would have to be way bigger than the block can take to make it equal 1.8 liters.
So, with the 1.6 crank in a 2.0 ABA block (if it will even fit) the bore would have to be increased to 84mm (if it can go that big) to get it real close to 1.8 liters.
An 83.5mm bore may be more doable and still nets you 1.77 liters which is still close enough to 1.8 liters that the manufacturers would still call it a 1.8.
Or you could use the 1.5 crank and just go as big as you can on the bore and live with whatever it gives you.
Lets say we make it an 83.5mm bore and the 73.4mm stroke. That will net you 1.628 liters.


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## Wraith04 (Jun 24, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

Diggatron says the ABA will go to 85mm, one time use though, no overbore after that.







What would the rod length have to be though?


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## ABF Jeff (Nov 16, 2005)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Wraith04)*


_Quote, originally posted by *Wraith04* »_Diggatron says the ABA will go to 85mm, one time use though, no overbore after that.







What would the rod length have to be though?

ABA with a 1.5 crank would need 168.69mm rods to use stock ABA pistons... that's pretty knarly for a 74mm stroke.


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (ABF Jeff)*

Yeah that's a nutty long rod.
The long rod VS short rod debate has been going on for a long time but in my opinion more than 6.25 inches (158.75mm) is really pushing it.
Here is another article that relates to the topic
http://www.stahlheaders.com/Lit_Rod Length.htm
I will do my best to translate a little.
long rods have their advantages.
The long rod will have less of a rod angle which reduces stress on cylinder walls. 
This lesser angle also reduces the stress on the rod because the piston speeds up and slows down at TDC and BDC at a lesser rate.
The short rod has it's advantages as well.
I think the article above explains it pretty well so I will just regurgitate that or better yet I will just cut and paste it.
Pressure above the piston times the area of the bore acts to create a force that acts through the connecting rod to rotate the crankshaft. If the crankshaft is looked at as a simple lever with which to gain mechanical advantage, the greatest advantage would occur when the force was applied at right angles to the crankshaft. If this analogy is carried to the connecting rod crankshaft interface, it would suggest that the most efficient mechanical use of the cylinder pressure would occur when the crank and the connecting rod are at right angles. Changing the connecting rod length relative to the stroke changes the time in crank angle degrees necessary to reach the right angle condition. 
A short connecting rod achieves this right angle condition sooner than a long rod. Therefore from a "time" perspective, a short rod would always be the choice for maximum torque. The shorter rod achieves the right angle position sooner and it does so with the piston slightly farther up in the bore. This means that the cyl pressure (or force on the piston) in the cylinder is slightly higher in the short rod engine compared to the long rod engine (relative to time).
Now you could always deck the block but I doubt you could remove 9 or 10 millimeters so you could get the rod down to an acceptable limit.
I suppose you could see what kind of bore you can do on the shorter 1.8 block and live with that.
If you could do 2mm over and make it 83 mm then, with the 1.5 crank, you would get 1.61 liters.
You could make power with this engine if you spun it quick enough but it would be really peaky and probably totally gutless below 6000 RPM. 
Keep in mind that this is all just my opinion and that this engine could work just fine if all the components were matched to the bottom end.
If I were to build an engine like this I would start with a block that has a much shorter deck height like the 1.8.
Then I would bore it as big as it would go (hopefully 83mm or so) and run the 1.6 crank.
This would give us 1.75 liters, which would work for me.
*Edit:*Oh yeah I forgot one thing that may make the other engine with the ridiculous rod length totally doable.
Costom pistons with a lower wrist pin height. 
This could get the rod down to an acceptable level in which case you would be golden.



_Modified by vwhammer1 at 2:10 AM 10-13-2007_


----------



## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
I suppose you could see what kind of bore you can do on the shorter 1.8 block and live with that.
If you could do 2mm over and make it 83 mm then, with the 1.5 crank, you would get 1.61 liters.
You could make power with this engine if you spun it quick enough but it would be really peaky and probably totally gutless below 6000 RPM. 
Keep in mind that this is all just my opinion and that this engine could work just fine if all the components were matched to the bottom end.
If I were to build an engine like this I would start with a block that has a much shorter deck height like the 1.8.
Then I would bore it as big as it would go (hopefully 83mm or so) and run the 1.6 crank.
This would give us 1.75 liters, which would work for me.
*Edit:*Oh yeah I forgot one thing that may make the other engine with the ridiculous rod length totally doable.
Costom pistons with a lower wrist pin height. 
This could get the rod down to an acceptable level in which case you would be golden.
_Modified by vwhammer1 at 2:10 AM 10-13-2007_

We are thinking on the same page here. Because of Rod to piston ratio, I do like the long rod idea (NO, not the 160+mm one!







), but I understand what you are saying about the shorter rod. I like the idea of starting out with the 1.8 style block (144mm rod), and going for broke on the bore (83.5 to 84mm max IIRC). I, like you, think the better part of valor would be custom pistons with a lower wrist pin. Weird Science. I've got a couple of old 1.8 blocks laying around, and an old set of ABA rods, who's with me?!?!?


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_
We are thinking on the same page here. Because of Rod to piston ratio, I do like the long rod idea (NO, not the 160+mm one!







), but I understand what you are saying about the shorter rod. I like the idea of starting out with the 1.8 style block (144mm rod), and going for broke on the bore (83.5 to 84mm max IIRC). I, like you, think the better part of valor would be custom pistons with a lower wrist pin. Weird Science. I've got a couple of old 1.8 blocks laying around, and an old set of ABA rods, who's with me?!?!?









This is Great!
I've got a buddy that is offering me a solid 1.7L motor in the near future. I'm very interested in trying to frankenstein a motor together.
I'll take look at those links above when I get back from work.
Thanks. http://****************.com/smile/emthup.gif


----------



## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Maybe some idea of the power potential of this engine will be the determining factor for some of you as to whether this engine makes sense.
So, I set this engine up in some engine simulation software I have and came up wit some numbers.
First off let me give you a run down on the specs.
I based everything on other manufacturers specs and then I added some things that I thought would be beneficial for this engine.
First off I started with a 1.8 block with an 84mm bore.
That is running a 1.5 liter crank with the stroke topping out at 73.4mm.
of course this is topped with a fully ported and polished head with 43mm intake valves and 34mm exhaust valves.
The compression ratio is a non pump gas friendly 12:1.
This would all be fed by a monster set of ITBs. (no motorcycle ITBs here)
A large tube header with no mufflers rounds out the exhaust.
The cam is based pretty closely on a couple different manufacturers.
It has 306 degrees of duration and .430 and .435 inches of lift on the intake and exhaust respectively.
All this equates to 199HP at 10000 RPM 
And peak torque of 135 at 6000 rpm
It makes at least 120 ft-lb from 4000 to 8500 RPM and at least 150HP from 6000 RPM and it only rises from there.
If that RPM scares you I ran the same engine with the 80mm stroke of the 1.6 engine. 
This gives us a 1.8 liter engine and moves the HP peak back to 8500RPM but it raises it slightly to 201HP.
The torque peak also rises to 145 ft-lb at 5500RPM 
This software is a little outdated but is accurate enough to give you an idea. 
And, as I said, my specs are based on real live parts and only a couple of things like valve sizes and cam lift were changed to levels that I thought would be possible.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_Here is a chart I found that I believe covers all of the bore and stoke specs of the engines we are talking about.
http://www.vintagewatercooleds...s.htm


That chart is a great resource, Thanks. http://****************.com/smile/emthup.gif


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
All this equates to 199HP at 10000 RPM 
And peak torque of 135 at 6000 rpm
It makes at least 120 ft-lb from 4000 to 8500 RPM and at least 150HP from 6000 RPM and it only rises from there.
If that RPM scares you I ran the same engine with the 80mm stroke of the 1.6 engine. 
This gives us a 1.8 liter engine and moves the HP peak back to 8500RPM but it raises it slightly to 201HP.
The torque peak also rises to 145 ft-lb at 5500RPM 


I have a couple of questions/comments:
1. Can a solid lifter head be built to rev to 10k rpm? 8500 sounds more realistic. (My real question: At what rpm do OEM solid lifters need to be replaced with Shim-under-bucket lifters?)
2. Can a bottom end safely rev to 10k rpm if it is fully balanced? I know from lurking in the 16v forum that the rods are usually the first thing to break at high rpm.
3. At what rpm level will the oiling system be inadequate? I would imagine that running a big gear pump would help, but can the distributor hold up at high rpm?
You mention using ITB's. According to one of the articles above, it is possible to utilize the intake pulses from the other cylinders when using a plenum intake. Doing this can help force the intake charge into the cylinder within a narrow rpm band. So, isn't it possible that a properly designed plenum intake could out peform ITB's?
You mention large tube header. Does this program give any information about the ideal exhaust port diameter, and header primary diameter? I believe the method of calculating this is outlined in the exhaust article above. 
I am thinking that an Audi 3A block would be the best, as it offers the largest bore, combined with a shorter block height when compared to the ABA. (Or you could use a 2.0 16v block)















Mike.


----------



## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

1. I am not sure about the different types of VW lifters.
As far as I knew there were hydraulic lifters and solid lifters.
The solid ones are definitely the ones you would want for high rpm use
2. If you are going to spin an engine up to 10k then you will more than likely want to step up to an aftermarket rod.
There may be some factory forged VW rods that could work with a good polishing and shot peening but aftermarket would be the way to go.
3. The oiling is something that I can't give you a definitive answer on.
Aeration would probably be the biggest problem at crazy rpm levels.
You might be able to fix this with some well placed baffles and a windage tray. If all else fails then a dry sump system may be your only option.
As far as the distributor goes I would ditch that in favor of some type of distributor-less ignition. That would eliminate that worry.
I think it would be tough to beat a big set of ITBs when it comes to airflow but I suppose with a little homework and some R&D it could work.
The software I have does not really get into many of the specifics when it comes to intake or exhaust design.
It just throws in some generic types of design to get you in the ball park.


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

Just to piggy back:
-At 10k rpm, I would be looking into dry sumping the thing. 
-The 3a block would be a good one for the reasons that you outlined.....the 9a engine would be great for the same reason PLUS the piston oil squirter's
-You can tune the intake runner length for the precise band in which you plan to have peak power. They do this in other forms of motorsport all of the time. I do, however, have a selfish preference to the idea of ITB's. 
-Hell, I would be game to try a set of peened/stress relieved rods at 10k (heaven help us all







).....I would need some arp's as well!


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## freshjive (Apr 25, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

Ive got a question for the motor calc thingie...what would the numbers be on a 1.5l diesel block with a 1.6l gas head with aprox 14:1 compression with ITBs, running e85?


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (freshjive)*


_Quote, originally posted by *freshjive* »_Ive got a question for the motor calc thingie...what would the numbers be on a 1.5l diesel block with a 1.6l gas head with aprox 14:1 compression with ITBs, running e85?









wow.
.....page two..........I own you.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (freshjive)*


_Quote, originally posted by *freshjive* »_Ive got a question for the motor calc thingie...what would the numbers be on a 1.5l diesel block with a 1.6l gas head with aprox 14:1 compression with ITBs, running e85?

Interesting... Unless I'm mistaken, isn't E85 that newer type fuel that's 15% ethanol? Is a 14:1 CR even possible on that type of fuel?


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## freshjive (Apr 25, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

No, e85 is 85% ethonol, and 15% gas. 14:1 is the perfect compression for e85


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (freshjive)*

Just remember, that there is a bunch more that goes into preoperly running E85. Including how much is needed (in general, you will need to run 30% more of it to achieve the same effect as gas). What I am trying to say is that even given its wonderful properties (equivalent of 114 octanne gas), it is less "powerful" than gas. No big, I suppose, when used in conjunction with EFI.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_The 3a block would be a good one for the reasons that you outlined.....the 9a engine would be great for the same reason PLUS the piston oil squirter's
-You can tune the intake runner length for the precise band in which you plan to have peak power. They do this in other forms of motorsport all of the time. I do, however, have a selfish preference to the idea of ITB's. 
-Hell, I would be game to try a set of peened/stress relieved rods at 10k (heaven help us all







).....I would need some arp's as well!

Thanks, I had forgotten about the oil squirters. http://****************.com/smile/emthup.gif
According to the GrapeApeRacing article, using a plenum helps to dampen the pressure waves in the intake tract. It also allows a cylinder to utilize the pressure waves created from other intake ports. The Helmholtz theory seems to only apply when using a plenum type intake, where one throttle body is feeding all 4 cylinders. Which leads me to my next two questions:
1. What plenum/throttle body layout is the best for feeding an inline 4 cylinder? (Ex: The most common is to have the Throttle Body at the end of the plenum, which I imagine does not provide even airflow to all 4 cylinders. I've seen a pic of an all-motor Honda with the throttle body feeding into the middle of the plenum, at a 90 degree angle.)
2. As the air travels thru the throttle body and into the plenum, it will loose velocity. What is the best way to taper the transition from the throttle body to the plenum? (I can draw a couple pics to illustrate if necessary)
Thanks,
Mike.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_Just remember, that there is a bunch more that goes into preoperly running E85. Including how much is needed (in general, you will need to run 30% more of it to achieve the same effect as gas). What I am trying to say is that even given its wonderful properties (equivalent of 114 octanne gas), it is less "powerful" than gas. No big, I suppose, when used in conjunction with EFI.

On a side note, does this mean that it would be better suited for a forced induction motor, where you could cram a lot of it into the cylinder at high PSI?


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

a couple of things:
1) I think that some of the online articles dealing with intake mani. design will put you in the right direction.....those guys are college Formula SAE guys that spend a lot of time with theories/formulas etc. that make my head hurt








2) I will retract my statement about E85 power potential. This topic has got me thinking more about the subject, so I started researching...check this out: http://www.drivingethanol.org/....aspx
3) I think that e85 is fine for NA or forced engines (hell, Ford Tauruses run on it), you just need to know the properties of the fuel that you are running!


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

E85 gets you 5-10% just due to the extra O2 in the fuel when run a little richer then 'normal.'


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

Let me try and cover a few things.
First off I noticed that I had a couple of specs that were off in the first set of dyno numbers I posted.
For the 84mm bore 80mm stroke the peaks should be as follows: 
206 hp at 8500 rpm and 149ft-lbs at 6000rpm.
For the 84mm bore and 73.4mm stroke the peaks should be as follows:
203 hp at 10000 rpm and 138ft-lbs at 6000rpm.
You can shift the peak hp around between 8500 and 10000 rpm by playing with the timing a little but that doesn't seem right to me so I just gave you the numbers I got with the timing set at 0 on both engines.
With all this talk about E85 and being an alternative energy/hybrid vehicle major myself, I decided to play around a little.
Just for fun I bumped the comp up to 14:1 and ran them on ethanol and the peaks for either engine jumps by 11 to 13 hp
That was pure ethanol but that should give you an idea.
As for the guy that wanted the diesel block running on ethanol 
the bore is 76.5mm and the stroke would be 80mm.
I ran the same ethanol engine with those specs and it nets me 203 at 10000rpm and 133 at 6000rpm.
This is compared to the 217 peak hp and 155ft-lb peak of the same ethanol engine with an 84mm bore.
I believe that article about ethanol already covered the fact that, because of the cooler air charge, you can make more power with ethanol if you supply the extra fuel it needs on the same engine.
However you can make even more if you build the engine to run on E85.
The higher octane and resulting cooler air charge due to the higher latent heat of vaporization makes it perfect for crazy high comp ratios without encountering detonation.
You could run 13 or 14 to 1 comp ratios on high octane race gas so this leads me to believe that you could go even higher with E85 (maybe 16:1!!!







).
It is also these characteristics of E85 that make it perfect for a boosted engine.
You could run higher boost levels before you reach the detonation point.
I think thats all for now


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## freshjive (Apr 25, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

Thank you for doing the calc on the e85.


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## ny_fam (Apr 3, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

When your running these equations, what volumetric efficiency are you using? 100%?


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_However you can make even more if you build the engine to run on E85. 

Hense the reason that I retracted my old statement. This thread has me jonesing to build up another NA motor!


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## Bajamonkey77 (Dec 12, 2006)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

Well, after reading all of that.. I'll ask, Why not just deck the block down, so you could use shorter rods. Then get custom pistons to move the wrist pin closer towards the top of the piston. (thats better?) Of course, by decking the block you would have to do some serious cam adjusting. just throwing out some more ideas.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Bajamonkey77)*


_Quote, originally posted by *Bajamonkey77* »_Well, after reading all of that.. I'll ask, Why not just deck the block down, so you could use shorter rods. Then get custom pistons to move the wrist pin closer towards the top of the piston. (thats better?) Of course, by decking the block you would have to do some serious cam adjusting. just throwing out some more ideas. 

Funny you mention that. My buddy and I were talking about this topic today, and we tried to figure out why the block can't just be decked down to compensate for the shorter stroke. Aside from the timing issue, the only thing we could come up with is that the holes for the head bolts would need to be lengthened and tapped...


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Yeah I think I mentioned earlier that you would need to take 9 or 10 millimeters off the top to get the rods down to an acceptable level. then you run into all sorts of other problems.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_Yeah I think I mentioned earlier that you would need to take 9 or 10 millimeters off the top to get the rods down to an acceptable level. then you run into all sorts of other problems.

What are the other issues faced with decking the block?
My only thoughts would be the timing belt length, and the threaded holes for the head bolts not being deep enough.
On another note: Could someone tell me what is Squelch?
Mike.


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Lets take another look at the whole "longer rod" thing. I remember when I built a 1.6 liter for SCCA E-Prepared class, I specified my JE pistons to be able to except the 1.8 liter (146mm) rod because of better rod to piston ratio's. What I am getting at is the piston was less likely to wobble around in the bore because the rod didn't get into extreme angles. 
BTW: This is quickly becoming a great thread, lets keep the good vibe going on here! http://****************.com/smile/emthup.gif


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_What I am getting at is the piston was less likely to wobble around in the bore because the rod didn't get into extreme angles. 


So, would I be correct to assume that longer rods provide the following benefits over shorter rods:
Less angle between the piston and wrist pin, when at the most "crooked" position of the crank stroke.
Less stress on the piston rings and cylinder walls.
Less stress on Bearings.
?








On a similar note: Isn't this one of the primary ideas behind motorcycle engines? Small displacement + high revs = high horsepower.
Just for the heck of it: I found that the differences between long rods and short rods made a lot of sense once I drew it out on paper. (Understanding the idea of having a 90 degree angle to the crank sooner in the power stroke) If anyone would like, I'd be happy to make a MS paint sketch of this.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

I found another good resource for NA tuning info.
It's a book called "How To Build Horsepower - Carbuerators and Intake Manifolds" By David Vizard. There are a couple sections in the book that go into the details of Helmholtz tuning, tuned port intakes, and what trumpets flow the best, among other things.
I did a search online and found this, which appears to cut out the info about carbs, and I would assume it gets more in-depth:
http://www.amazon.com/How-Buil...72245
I also have a good book titled: "How to Build, Modify, and Power-tune Cylinder Heads"


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## Bajamonkey77 (Dec 12, 2006)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Well, I'm sitting here thinking.. if the holes for the head bolts couldn't be tapped and lengthened, just make spacers, to put between the head and the top of the bolts. Then another question, Do the 1.5 engines have shorter timing belts? if not, the head would have to be taller, right?


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Bajamonkey77)*


_Quote, originally posted by *Bajamonkey77* »_Well, I'm sitting here thinking.. if the holes for the head bolts couldn't be tapped and lengthened, just make spacers, to put between the head and the top of the bolts. Then another question, Do the 1.5 engines have shorter timing belts? if not, the head would have to be taller, right? 

That's a good idea, my only concern would be if there were enough thread to grab... I suppose it all depends on how much you shave the block down (9-10 mm as stated above) I'd bet that some ARP hardware couldn't hurt...
Not sure about the 1.5L timing belt. Maybe they made up the difference in the piston dish, or the combustion chamber?


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## vwhammer1 (Jul 27, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

I would say that at this point there will be a fair amount of fabrication involved. 
I am sure there is a cogged belt out there that would fit the bill for the timing belt.
If not, then some type of tentioner could be fashioned to take up the slack.
Better yet why not make a new cam and crank gear then make some idler gears and make the whole thing gear driven. 
Think what that would sound like at 10k
The deck height of the 1.5 block should be the same as the all of the blocks up to the 1.8 so they probably use the same parts for timing.


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
Better yet why not make a new cam and crank gear then make some idler gears and make the whole thing gear driven. 
Think what that would sound like at 10k


INSANITY!!!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I love it!


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## lamarchambers (Dec 25, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

i can assure you that long rod and long stroke will out do a short stroke any day. ask any engine builder and he will take stroke over bore any day. ABA block with stock pistons at 0 deck will give you about 13-1 ratio. same engine with 2.0- 16 valve pistons will give you about 15-1 ratio. just change the pin bushing to 16 valve and then add the JH head and a 350 cfm holley. my vw runs a 82 stroke with 94mm pistons and runs mid 6s in a 1/8. 
i have a ABA set up like this that i would sell cheap. 
call 770-227-7860 Lamar


_Modified by lamarchambers at 2:25 AM 10-21-2007_


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (lamarchambers)*


_Quote, originally posted by *lamarchambers* »_i can assure you that long rod and long stroke will out do a short stroke any day. ask any engine builder and he will take stroke over bore any day. 

I find this hard to believe. People seem to have a lot of trouble getting ABA/JH motors above 150 hp. (guessing). On the other hand, these small displacement VW motors seem to be able to achieve a higher hp. Granted, they are race motors with high comp... On that note, why is it that formula cars use high revving small displacement motors to get such high horsepower? (Or motorcycles)

_Quote, originally posted by *lamarchambers* »_my vw runs a 82 stroke with 94mm pistons and runs mid 6s in a 1/8.

Wait, so you're saying that your VW motor is running 94mm pistons, and an 82mm stroke? So, you are in-fact running an oversquare setup, which is exactly what we have been talking about.


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

It's oversquare, but not as much as it could be. Many people run 94mm pistons with smaller stroker cranks like a 74 or 78.4. Still, all are a bit bigger then the stock 69mm stroke.


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## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (need_a_VR6)*

You guys are obviously talking about aircooled cars. I am all ears for any water cooled engine that you can get that kind of piston into. There are amore than a few ways to get more air into a combustion chamber, stroke is one, and revs are another.....we are exploring the revs side of this equation. It's a given that VW guys go the stroke route for a couple of reasons:
1) That's how our engins are originally built
2) The biggest piston that yop can fit is an 85mm (ABA only). 

....We are considering the implications of shorter stroke/ increased bore/ more revs to make power. Sort of like the cars from the land of the rising sun.


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_You guys are obviously talking about aircooled cars. I am all ears for any water cooled engine that you can get that kind of piston into. There are amore than a few ways to get more air into a combustion chamber, stroke is one, and revs are another.....we are exploring the revs side of this equation. It's a given that VW guys go the stroke route for a couple of reasons:
1) That's how our engins are originally built
2) The biggest piston that yop can fit is an 85mm (ABA only). 

....We are considering the implications of shorter stroke/ increased bore/ more revs to make power. Sort of like the cars from the land of the rising sun.









Actually, As far as I know the conversation has not been about aircooled motors at all. It has been mentioned that there are several VW watercooled cranks that are smaler than 85mm. The 1.6 gas = 80mm and 1.5 gas = 73.4mm. The 1.5 diesel = 80mm. So, any of these cranks under a 1.8L or 2.0L block will achieve an Oversquare setup. The problem lies in increasing the CR to a useable level, since the shorter crank will lower it.
Yup, I realized a while back that we are talking about similar ideas to that of Japanese engines, and sport bike engines. The main drawback here is that our VW 8v heads don't breathe as well; which is why I'm also inquiring as to how we can work a head/intake to breathe better.


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## need_a_VR6 (May 19, 1999)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Don't forget that a lot of the 'little' cranks use smaller rod journals. Custom rods or a lot of welding and machining will make it work.


----------



## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_It's oversquare, but not as much as it could be. Many people run _*94mm pistons *_with smaller stroker cranks like a 74 or 78.4. Still, all are a bit bigger then the stock 69mm stroke.

This is why I ref. aircooled........


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*


_Quote, originally posted by *Diggatron* »_
This is why I ref. aircooled........

Ahh, I didn't catch that...








On another note, If anyone has not seen this camshaft thread in the 2.0L forum, take a look. It is very informative:
http://forums.vwvortex.com/zerothread?id=3467526


----------



## tdogg74 (Mar 1, 2002)

This is a good thread. I never would have thought to find a thread of this calibre in the Fab forum. Keep it up guys.


----------



## Holden McNeil (Jul 26, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
Ahh, I didn't catch that...








On another note, If anyone has not seen this camshaft thread in the 2.0L forum, take a look. It is very informative:
http://forums.vwvortex.com/zerothread?id=3467526

I just read that last night and it's making me second guess my cam choice....


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (tdogg74)*


_Quote, originally posted by *tdogg74* »_This is a good thread. I never would have thought to find a thread of this calibre in the Fab forum. Keep it up guys. 

Thanks http://****************.com/smile/emthup.gif
So, I am wondering if anyone has a chart of the different Rod lengths and journal sizes of VW motors over the years? 
The site posted on the first page is great because it has the bore and stroke measurements. I'd like to take it a step further and have a chart of all the different measurements that concern the cranks and rods.
Edit: Bertil's Site is pretty interesting, as Bertil has been working 8v motors for a long time:
http://www.bertilsengines.com/about.html


_Modified by Jettaboy1884 at 4:58 PM 10-24-2007_


----------



## tdogg74 (Mar 1, 2002)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Holden McNeil)*


_Quote, originally posted by *Holden McNeil* »_
I just read that last night and it's making me second guess my cam choice....
















Which is exactly why I wrote it...in hopes that at least one person can make an informed descision. Lemme know if you have any questions...just shoot me a PM. http://****************.com/smile/emthup.gif


----------



## Issam Abed (Feb 12, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*


_Quote, originally posted by *need_a_VR6* »_Don't forget that a lot of the 'little' cranks use smaller rod journals.

Nope,got an 80mm crank right here with a 48mm rod journal.Was going to use it for a destroked ABA then the Oettinger 99mm unit came along.With 159mm & an 80mm stroke I am looking @ an almost 2.0 rod ratio and 1773cc!
Can anyone say REV CITY?


----------



## need_a_VR6 (May 19, 1999)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
So, I am wondering if anyone has a chart of the different Rod lengths and journal sizes of VW motors over the years? 

The only good info I've found is : http://mysite.verizon.net/janvdb/vw/PowerUpgrades/
Under the collins documents. 
Issam, not sure what motor you found that crank in...

_Quote »_The early 1.5L and all 1.6L motors used a 80mm forged crank; the '78 1.5L used a 73.4mm cast crank; 1.7L & 1.8L motors both used 86.4mm forged cranks, but with different connecting rod journal diameters (more on that in 'connecting rods')...
VW made three different connecting rods. 1.6 (stud & cap); Audi (Bolt into rod); 1.8 (stud & cap). The 1.6 & Audi rods fit both the 1.6 & 1.7L crank and have the same length. The 1.8 rod is a bit longer, and has a smaller journal & piston pin diameter.

So what you're saying is you have a super early 80mm crank with the late rod journal diameter?


----------



## Issam Abed (Feb 12, 2004)

*Re: (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_So what you're saying is you have a super early 80mm crank with the late rod journal diameter?

Its a late crank from an AKL motor.The crank snount will need to be modified to replicate that of a 037 crank.


----------



## Diggatron (Sep 4, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
Nope,got an 80mm crank right here with a 48mm rod journal.Was going to use it for a destroked ABA then the Oettinger 99mm unit came along.With 159mm & an 80mm stroke I am looking @ an almost 2.0 rod ratio and 1773cc!
Can anyone say REV CITY?









.....just what I was thinking! http://****************.com/smile/emthup.gif


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
Its a late crank from an AKL motor.The crank snount will need to be modified to replicate that of a 037 crank.

Any chance you want to sell it?
Or, could you tell us what cars this could be found in?
Back to the original topic:
So, we've talked a lot about building a bottom end that will rev high, by using pistons that are slightly larger than the stroke. My question is: If we're talking in terms of an 8v counterflow motor - How much can an 8v be made to breathe at the top-end? At about what point does the head max out (in terms of about 1.6-1.7L of displacement)?
What about balancing/lightening a 1.6L bottom end and tossing on a properly worked GTI cylinder head and raising the compression ratio? Would that really perform any less than the custom Oversquare engine that we're talking about?
Mike.


----------



## Issam Abed (Feb 12, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_Any chance you want to sell it?

Sure,send me a pm with an offer.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
Sure,send me a pm with an offer.

I'll PM you about it.
Back on Topic: I'd like to talk about the intake tract. Example: How do you determine the optimal size for a throttle body? (or in the case of ITB's how do you determine the optimal size?)


----------



## infinity (May 12, 2004)

Nice thread!


----------



## vwhammer1 (Jul 27, 2004)

*Re: (infinity)*

Let me try and get the discussion flowing again.
First I would be willing to bet that you could get away with using a whole 1.6 block and just don't go so big with the bore.
The stock bore on the 1.6 is 79.5.
So, let's say we take it to a modest 80.5
That would give us 1.65 liters in what is technically an oversquare design.
With everything being as light as it could be I see no reason why this engine couldn't make the power we are looking for.
Of course we are assuming that the engine is strong enough to handle the abuse it would surely receive.
From what the dyno simulator says we are looking at 199hp at 8500 rpm. 
Pretty close to what we were looking at with the other engines without all the expense.
I love this type of conversation and this type of engine build. 
It goes on to prove what can be done if you think outside the box 
But, let's face it.
We can make a lot more power for a lot less money. 
There are only two reasons to build anything like this:
1. You have some type of rules that regulate what you can do to your engine 
2. Cool factor
Honestly reason number two is enough for me but it really does go against my "form follows function" motto.
To really bring this whole thing into perspective we need to look at the power that could be made if we took the traditional route.
Let's just keep everything the same and change the bore and stroke to something that is capable with the ABA block.
So we have a 84mm bore and a 92.78mm stroke.
If I plug this into the dyno sim we get 206hp at 7500 rpm and 167 ft-lbs at 5500.
We can see that the numbers are not to far off of what we were looking at with our theoretical 1.8 engine and not even that far off of the 1.6 we are talking about above.
Would the ABA be more street-able?
It could be.
But, the bottom line is our theoretical engines would be more efficient for no other reason than it makes more power with less cubic inches.
If we are wrong in our ideas someone should also tell Ferrari that their engines are stupid and they could make more power if they stepped up the CCs a little. 
But, something tells me that they won't give your advice much consideration.
I am not even going to pretend that I know why Ferrari chooses to build smaller displacement engines but they work and if used in the right situation they work very well. 
Well it's getting late and I think I should stop there and finish my thought tomorrow.
I kind of jumped around a lot in this rant but I wanted to get as much typed as I could before I lost my train of thought and forgot most of the stuff I was thinking.
That should give us something to talk about for a day and I will be back tomorrow with some more answers so some of the other questions that have been brought up, such as air requirements for a specified HP. 


_Modified by vwhammer1 at 1:38 AM 10-30-2007_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwhammer1)*

First, I would like to say Thanks for bumping this back up.
Second, I have a couple questions/comments on a few things you've said.

_Quote, originally posted by *vwhammer1* »_Let me try and get the discussion flowing again.
First I would be willing to bet that you could get away with using a whole 1.6 block and just don't go so big with the bore.
The stock bore on the 1.6 is 79.5.
So, let's say we take it to a modest 80.5
...
From what the dyno simulator says we are looking at 199hp at 8500 rpm. 
Pretty close to what we were looking at with the other engines without all the expense.


Just wondering: Could it be safely bored out to 81mm so that we could use 1.8L pistons? (I have a 1.8L 16v laying around that I can steal the pistons from, which would bump up the C/R as well.)
What Compression ratio and Volumetric Efficiency are you using with this calculation?
If I'm going to build one of these motors, I'd like it to be able to run on pump gas. So, what's the max compression ratio that 93 octane can run with? (And at that compression ratio, which I assume will be lower than what you are calculating, will the motor make anywhere near the same power?)

_Quote, originally posted by *vwhammer1* »_
I love this type of conversation and this type of engine build. 
It goes on to prove what can be done if you think outside the box 
But, let's face it.
We can make a lot more power for a lot less money. 
There are only two reasons to build anything like this:
1. You have some type of rules that regulate what you can do to your engine 
2. Cool factor


I enjoy trying different things. Not really for the sake of being different than others, but more for the reason that I can say that I tried something out of the ordinary and made it work, even if it's not the best way of doing it...
I also like the idea of spinning an 8v to 8k+ RPM's and still making power when everyone thinks you need a 16v to do it. 

_Quote, originally posted by *vwhammer1* »_To really bring this whole thing into perspective we need to look at the power that could be made if we took the traditional route.
Let's just keep everything the same and change the bore and stroke to something that is capable with the ABA block.
So we have a 84mm bore and a 92.78mm stroke.
If I plug this into the dyno sim we get 206hp at 7500 rpm and 167 ft-lbs at 5500.
We can see that the numbers are not to far off of what we were looking at with our theoretical 1.8 engine and not even that far off of the 1.6 we are talking about above.


My only question towards this statement is that I have heard of small displacement NA race motors making around 200hp and up; but I've never seen any ABA's making above 175hp. NA.
I'm looking forward to your thoughts.















Mike.




_Modified by Jettaboy1884 at 11:14 AM 10-30-2007_


----------



## vwhammer1 (Jul 27, 2004)

*Re: (Jettaboy1884)*

I have been sticking with a 12:1 comp ratio for all of these engines running on gasoline.
I bumped it up a couple of times to 14:1 when I ran them on ethanol.
I would not run any where near either one of those numbers if I was going to run on pump gas.
I would stick to around 10:1 
As far as the VE number, it calculates that for me and from 4500 to 10000 rpm it is above 100 percent with a peak of 111.5 % 
I am not sure which engine we are talking about anymore so for conversations sake lets look at the most recent engine with an 80.5mm bore and a 80mm stroke
To answer the question I ran our theoretical engine with 10:1 copression and came up with the folloing numbers:
186hp @ 8500rpm
132ft-lbs @ 6000rpm
peak volumetric effiency of 110%
All of this from 1.65 liters
Those numbers only changed 1 hp and 1 ft-lb when I changed the bore to 81mm. 
I don't know the answer to your question about boring the 1.6 block so you would have to look into that.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwhammer1)*

Thank You,
I think it's very important in this case to note that a properly designed intake and exhaust tract is absolutely fundamental in extracting this kind of power from a VW 4-cyl.
I would like to know: Is a 10.5:1 or even an 11:1 Compression ratio even feasable on a street motor? (I will have to look around in my area and see what's the highest available octane gasoline.) In that case, Is it possible to use a slightly higher compression ratio if one were to use octane booster in the gas?


----------



## vwhammer1 (Jul 27, 2004)

*Re: (Jettaboy1884)*

I think with an octane booster you could probably get away with more comp.
If you knew or had someone who knew how to really tune stand alone EFI You could probably even go higher on pump gas without the booster.
There are several factory cars that run factory comp ratios over 10.5.
The Honda S2000, Several BMWs and even the old Audi V8 that is going in my V8 Rabbit project runs more that 10:1.
11:1 would probably be the practical limit.
On the topic of intake size and flow capabilities I can tell you that it is complicated.
Theoretically you can do some math based on your desired HP, engine displacement, the air required to mix with a given amount of fuel to make a single HP and the volume of the tubes that will be feeding the engine. and come up with some type of numbers for the proper dimensions for you r intake. 
But there are so many variables that there is no way to come up with a general rule of thumb to make this sort of thing simple.
Trial and error is about the only real way to squeeze every drop of HP out of an engine.
You could go the difficult and drawn out math route but that only gives you theoretical results and anyone that has done any chemistry or physics can tell you that your actual results and your theoretical results are almost never the same.
You will need a dyno and some some type of tune-able prototype intake and exhaust to come up with your ideal dimensions and that about the only way to do it.
You could use some dimensions from some other engines and see if that works for you but it will still boil down to trial and error on the dyno.
On the topic of cylinder head design you will have to pull out all the stops.
If you plan to use an 8 valve head, (and you do) it will take every tip and trick in the book to get the flow needed for this type of engine.
We are talking exotic multi-angle valve jobs, seriously over-sized light weight valves with the stems necked down, light weight springs, lifters, retainers and a port and polish that would best be accomplished by a CNC machine.
By my best guess you will spend at least half of the total engine budget on the cylinder head and it's components alone.



_Modified by vwhammer1 at 4:22 PM 10-30-2007_


----------



## Issam Abed (Feb 12, 2004)

*Re: (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
With everything being as light as it could be I see no reason why this engine couldn't make the power we are looking for.

If your looking for light then you should use an Aluminum block over the Iron one.The weight difference is ~ 50lb's or so.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
If your looking for light then you should use an Aluminum block over the Iron one.The weight difference is ~ 50lb's or so.

Just for the record, I believe he is reffering to the rotating and reciprocating components, such as Crank, IM shaft, Rods, pistons, valvetrain, etc. Having a lighter block shouldn't have any affect on the max RPM. Of course you are correct in saying that less weight is always better, I just wouldn't want anyone to assume it will affect RPM's. http://****************.com/smile/emthup.gif 
On that note: Are there any VW/Audi 4-cyl blocks that are Cast Aluminum? (I did see the thread where someone made their own Aluminum 16v block, but that doesn't apply







)


----------



## Issam Abed (Feb 12, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_On that note: Are there any VW/Audi 4-cyl blocks that are Cast Aluminum? (I did see the thread where someone made their own Aluminum 16v block, but that doesn't apply







)

That aluminum block was made from Billet.They are 2 versions of Cast aluminum blocks but both were for the later style internal water pump blocks.


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## Diggatron (Sep 4, 2004)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
That aluminum block was made from Billet.They are 2 versions of Cast aluminum blocks but both were for the later style internal water pump blocks.

What are the engine codes for those?


----------



## Issam Abed (Feb 12, 2004)

*Re: (Diggatron)*


_Quote, originally posted by *Diggatron* »_What are the engine codes for those?

AKL & ALT.Unfortunately for you (and me) is that only 2 countries got these engines and they are few and far between.I have NEVER seen just the block @ any of the breakers which meant that if I wanted one I would have to buy a complete engine (which I did).If you want a block let me know as I have 1 AKL & 1 ALT kicking dust.


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## Diggatron (Sep 4, 2004)

*Re: (Wizard-of-OD)*

What's the displacement, cylinder head, and price?


----------



## Issam Abed (Feb 12, 2004)

*Re: (Diggatron)*


_Quote, originally posted by *Diggatron* »_What's the displacement, cylinder head, and price?

PM me for details.


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
...My question is: If we're talking in terms of an 8v counterflow motor - How much can an 8v be made to breathe at the top-end? At about what point does the head max out (in terms of about 1.6-1.7L of displacement)?


I just want to bring up my question above, and see if anyone can answer this for me.
Is a counterflow 8v head capable of being more than 100% efficient with the proper port work?


----------



## ny_fam (Apr 3, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
I just want to bring up my question above, and see if anyone can answer this for me.
Is a counterflow 8v head capable of being more than 100% efficient with the proper port work?


VE= 3456 x CFM/CID x RPM
210 CFM at 6500 rpms will get you 100%
you'll need a special intake system to do that with out forced induction.








or 190 CFM at 5500 rpms with get you 100%
Or a Stock setup
130 CFM at 4000 rpms is 100% VE


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## Jettaboy1884 (Jan 20, 2004)

Let's bump this back up!


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## Issam Abed (Feb 12, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_Let's bump this back up!

NP....the ALT in race form:


----------



## g60_c (Nov 15, 2001)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
NP....the ALT in race form:









what the carp is THAT!?!?!


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## Wraith04 (Jun 24, 2004)

*Re: (g60_c)*

Hmmm, looks like dry sump, aluminum block, 16V. COP, on ITB's or that's that new airplane wing intake.


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Wraith04)*

I'm not really that familiar with VW 16v motors, but I can't spot a single OEM 16v part on that motor...


----------



## vwhammer1 (Jul 27, 2004)

*Re: (Jettaboy1884)*

i think it is a 20 valve engine and the big intake would be sticking out of the side of a open wheeld car


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## Diggatron (Sep 4, 2004)

*Re: (vwhammer1)*

Whatever it is, I am in love!


----------



## infinity (May 12, 2004)

*Re: (Diggatron)*

VW actually bored out and de-stroked the 16v motor for the mk3 works rally car!!


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## Jettaboy1884 (Jan 20, 2004)

*Re: (infinity)*


_Quote, originally posted by *infinity* »_VW actually bored out and de-stroked the 16v motor for the mk3 works rally car!!









Need more info!
Regarding the original topic: I have a few more questions about NA tuning, but have been too busy to slap together a few MS Paint images to illustrate my questions...


----------



## infinity (May 12, 2004)

*Re: (Jettaboy1884)*

I know were talking about the 8v engine, buts its still an NA motor works spec's were;
bore 84mm
stoke: 90mm
260hp @ 8-8.1k
ABF base block


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## vwhammer1 (Jul 27, 2004)

*Re: (infinity)*

As small as some of the parts are in the VW engines I don't doubt that, with some well chosen light weight parts, you could make an undersquare engine rev as well as an oversquare engine if both were built within the realm that we are talking about here.
And you would even have the extra displacement to boot.
It's a tough call.
More revs (if you need them), less displacement, less stress, decent power
OR slightly less revs (enough probably), more displacement, more stress on the components and decent power.
Which would be better? 
Who knows 
They both have friction problems associated with them, one on account of more revs and the other on account of faster piston speed. 
As I said it's a tough call.
260hp sounds crazy and I couldn't even get close to that number in my simulation software but they do some pretty amazing stuff in the rally world.
When I put the numbers above into the simulator the peak HP dropped but only slightly.
it was actually higher throughout the rev range before the peak at 7500.
The peak torque went up around 20ft-lbs and averaged a 20 ft-lb increase in the revs before the peak but started dropping off rapidly after that to end up in the same place as the short stroke engine for most of the rev range after the peak.


----------



## Issam Abed (Feb 12, 2004)

*Re: (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_i think it is a 20 valve engine and the big intake would be sticking out of the side of a open wheeld car

Correct,it is the engine Volkswagen provided to be raced in Formula 3.Its an aluminum block 20V head.Whether it was running FSi or not is unclear as at first next to coil pack #1 had looked like the FSi fuel pump but now I see its the fuller cap.









_Quote, originally posted by *infinity* »_I know were talking about the 8v engine, buts its still an NA motor works spec's were;
bore 84mm
stoke: 90mm
260hp @ 8-8.1k
ABF base block

Interesting ....this is the VW Rally engine - NA 20V








on the Skoda WRC motors they went with:
Bore = 82.5mm
Stroke = 93.5mm
So far in existance VW (along with oettinger) has made the following strokes:
80mm, 86.4mm,89mm,92.8mm,93.5mm,94.5mm,95.5mm,99mm
There has been rumours of 100+mm strokes but I have yet to see them.


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## infinity (May 12, 2004)

Wiz
those figures are for a mk3 golf rally car, The 90mm crank has a VWM part number. I'll dig out some spec sheets


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## Issam Abed (Feb 12, 2004)

*Re: (infinity)*


_Quote, originally posted by *infinity* »_The 90mm crank has a VWM part number.

If it starts with G then its unobtainable








You know how many VWMS catalogs I look @ and drool over what could if should?Its not cool...


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## Proulus (Jan 21, 2005)

*Re: (Wizard-of-OD)*

Wiz, doesn't VW also make 70.6mm and 75.6mm cranks. from the 1.0L motor and the 1.4tsi. I read that somewhere...


----------



## Issam Abed (Feb 12, 2004)

*Re: (Proulus)*


_Quote, originally posted by *Proulus* »_Wiz, doesn't VW also make 70.6mm and 75.6mm cranks. from the 1.0L motor and the 1.4tsi. I read that somewhere...

Yes but has anyone fitted one of those inside of a 058 block?


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Wizard-of-OD)*

Allrighty, I have another question:
Is it true that Polishing an intake manifold to a mirror smooth finish can actually reflect heat?
Also: Can someone tell how to properly size a throttle body to an engine? It seems that people always feel that "bigger is better" and I have learned that this far from true.
Thanks.
BTW: Have a happy Turkey Day!


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## infinity (May 12, 2004)

Factors influencing size are; Power output, RPM, cylinder head design, cylinder capacity, position of the throttle body in the inlet tract and position of the injector.
Choice of bore size is a balanced compromise resulting from the following;
1) A larger bore leads to lower flow resistance, but obeying the laws of diminishing returns.
2) A smaller bore leads to better throttle control and response and improved fuel mixing.
3) The system should be considered in total - from (at least) trumpet flange to cylinder and proportioned accordingly.


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## ramdmc (Jul 25, 2005)

*Re:*

If anyone's interested, I know of a 218hp counterflow 1945 cc 8v that's for sale in Luxembourg, he will ship to N/A for around 300-400 Euro. He wants $2500 Euro for the bare motor (inc header) or $3200 Euro with Pierburg ITBs. It was dynoed with the ITBs so would make less ponies with traditional intake. 
It's a fresh rebuild so zero miles. Not a streetable option imho.
I was looking at buying it but like everyone here, I have project ADHD and a baby on the way, so I have to get my priorities straight. 
This is a link to the original auction http://cgi.ebay.de/ws/eBayISAP...0.lVI 
He speaks English so no worries there.
Man, if I didn't have a baby on the way, I'd buy this in a heartbeat.
I'll see if I can dig up a video of it running in the car before the rebuild.
RC


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## Jettaboy1884 (Jan 20, 2004)

*Re: (infinity)*


_Quote, originally posted by *infinity* »_Factors influencing size are; Power output, RPM, cylinder head design, cylinder capacity, position of the throttle body in the inlet tract and position of the injector.
Choice of bore size is a balanced compromise resulting from the following;
1) A larger bore leads to lower flow resistance, but obeying the laws of diminishing returns.
2) A smaller bore leads to better throttle control and response and improved fuel mixing.
3) The system should be considered in total - from (at least) trumpet flange to cylinder and proportioned accordingly.


Very Cool, Thanks.
After reading your reply though, I wonder: Are you specifically reffering to ITB's?
On another note:
Boost gauges typically show a vaccum reading. Is there any potential in using a vaccum gauge to see at what RPM your engine is pulling air most efficiently? For example: I would think that when the intake tract is supplying the perfect amount of air to each cylinder, the vaccum in the intake would be very low... Is this true?
I would think that in an intake setup with a plenum, you could put a vaccum gauge in every runner and find out how effectively the air is distributed under actual conditions. On the other hand, I don't see how this can be useful for tuning unless you can constantly remove the head and intake to tune them...
Mike.


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## elmer fud (Aug 5, 2003)

anyone see th 240hp N/A SEAT ibiza in the nov 07 pvw. 
slick!


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## ny_fam (Apr 3, 2004)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
Very Cool, Thanks.
After reading your reply though, I wonder: Are you specifically reffering to ITB's?
On another note:
Boost gauges typically show a vacuum reading. Is there any potential in using a vaccum gauge to see at what RPM your engine is pulling air most efficiently? 


Yes this is a good idea, I'd like to see the data too. Here are some issues to think of. With CIS the air flow plate will always be a restriction. Also the intake tube has a positive effect on the air pressure in the plenum if the intake tube is the right diameter and length. Thats is if the intake tube its sized correctly at the peek RPM. Then at WOT and the tuned RPM the plenum air pressure should be positive(Also give the correct TB size or at least close)

_Quote »_
For example: I would think that when the intake tract is supplying the perfect amount of air to each cylinder, the vaccum in the intake would be very low... Is this true?


True and false - True some point after TDC, then gost postive just as the valve closes, and kind of unknown during exhaust cycle, then with the induction waves ... its hard to measure. But a MAP sensor would work fine data logged with an RPM signal you could see what pressue +/- you have.

_Quote »_
I would think that in an intake setup with a plenum, you could put a vaccum gauge in every runner and find out how effectively the air is distributed under actual conditions. On the other hand, I don't see how this can be useful for tuning unless you can constantly remove the head and intake to tune them...
Mike.

A good tuning shop with a flow bench will flow the head with the manifold attached, and with the standard air straighter. If the manifold doesn't help the head flow better or at least the same than with the standard air straighter you need a better manifold








Cheers
ny_fam


----------



## elmer fud (Aug 5, 2003)

formula 3 race car. 


_Modified by elmer fud at 10:24 PM 12-2-2007_


----------



## elmer fud (Aug 5, 2003)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
VW actually bored out and de-stroked the 16v motor for the mk3 works rally car!! 
Need more info!
Regarding the original topic: I have a few more questions about NA tuning, but have been too busy to slap together a few MS Paint images to illustrate my questions...

and it made 260hp NA, go to bildon look at there vwms documents and download the mk3 kit car pdf. it has all the mk3 rally car parts and numbers








have fun dreaming.........


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (elmer fud)*


_Quote, originally posted by *elmer fud* »_
and it made 260hp NA, go to bildon look at there vwms documents and download the mk3 kit car pdf. it has all the mk3 rally car parts and numbers








have fun dreaming.........









Thanks for the tip, I'll go check out their site. http://****************.com/smile/emthup.gif 
Here's another question that I have. Cross posted with the other thread in the 8v Forum:
What are the steps for determining the length of the intake runners for Helmholtz and resonation tuning:
I would think that the best way to go about doing this would be to first port & polish the cylinder head and determine the peak CFM. Then, Given the displacement of the motor, figure out at what RPM the motor sucking in that quantity of air. *Given no other losses in the intake tract, Would this be the point where the motor can reach 100% Volumetric Efficiency?* I would assume that as as the RPM's demand more CFM than the head can flow, the motor will quickly drop from 100% Volumetric Efficiency...
So now I wonder: Is this the peak RPM that you'd want to single out for Helmholtz tuning, since the motor should theoretically be at 100% VE at this point? If not, How do you determine what RPM to tune the intake and exhaust tract for optimal pulse tuning and scavenging?
Thanks.


----------



## elmer fud (Aug 5, 2003)

"What are the steps for determining the length of the intake runners for Helmholtz and resonation tuning:"
I tryed to figure this stuff out a long time ago, the math involved seemed very tricky, also the length is useuly to long to fit in the engine bay so then you have to find a ..... wel I forget what they called it but it was a way of still geting some of the full lengths resonation. I bet some one on here can explane better..... or realy explane it as I did a very crappy job.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (elmer fud)*

I understand exactly what you are talking about. The article from Grapeaperacing explains this in detail. http://****************.com/smile/emthup.gif


----------



## jerrymic (Apr 19, 2007)

*Re: (Jettaboy1884)*

http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (jerrymic)*

Bump.
I'm super excited because my Wife got me an early Christmas present. We picked up a '91 Taurus SHO last night. About 160k miles, with a shot clutch. The engine runs good, but I plan on doing the 60k maintenance when we yank it out...








If anyone is interested, I'll post up a pic or two. I've fallen in love with the motor allready. The intake manifold is a nice piece of engineering, and can still benefit from some modification.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

To follow-up my last post, I was lurking in an SHO forum that I like, and came across this very cool thread:
http://www.shoforum.com/showthread.php?t=83786
In the thread are a lot of links to Patent pages regarding intake manifolds with variable runners, or variable plenum volume... One of the patent pages has links to a lot of other similar patents.
Have a look, and check out the other patents listed along the lower-left side. Check out the drawings -> Definitely some very interesting stuff. http://****************.com/smile/emthup.gif 
http://www.google.com/patents?...90464


----------



## vwhammer1 (Jul 27, 2004)

*Re: (Jettaboy1884)*

Hi gang sorry I have been absent for a while.
I have been real busy with a lot of things.
In regards to the intake tuning all i can say is this and it may not be very helpful.
The math involved is very... well... involved and I could not even begin to tell you how to do it. 
I can tell you, however that the math is necessary to find out a relatively simple thing.
And that thing is the frequency of the waves of pressure that are traveling down the length of the intake.
The goal is to have the length just right so you do not get waves bouncing around in the tubes disrupting airflow.
The biggest problem is that you cannot generally tune a manifold design so that it is perfect throughout the entire rev range. 
You have to pick low end or top end or make some compromises and design a variable runner intake. much like the SHO or my Audi V8 among others.
And that is about all I know.
I will be finishing my mechanical engineering degree starting next fall.
Give me some time to finish the difficult math and physics classes and I may be able to explain a little better and in more detail if someone has not answered by then.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_... or make some compromises and design a variable runner intake. much like the SHO or my Audi V8 among others... 

I didn't know that your Audi V8 had variable runners.
Please post pics!


----------



## vwhammer1 (Jul 27, 2004)

*Re: (Jettaboy1884)*

I guess it's not really variable. It has a dual runner intake from the factory. It flows through long runners at low RPM but then a flap or valve or something opens up at higher RPM to allow air to flow through shorter runners.
I think the SHO works along the same principle.
Anyhow I scrapped it to make way for 8 individual T bodies.


----------



## rivethead (Nov 27, 2004)

*Re: (vwhammer1)*

Cars with variable intakes.
Audi 2.0 four, V6 and S-models V8 - 2-stage variable length manifolds 
Audi A-models V8 - 3-stage variable length manifolds 
BMW new V8's DIVA - variable length manifolds, 2-stage ? 
Fiat / Alfa / Lancia Super Fire engines - 2-stage variable length manifolds 
Ferrari 360 Modena and 550 Maranello - 2-stage variable length manifolds 
Ford Duratec 2.5 and 3.0 V6 - 2-stage variable length manifolds 
Honda Integra Si 2.0, 3.2 V6 Type S - 2-stage variable length manifolds 
Honda Legend - 3-stage unknown system 
Honda NSX - 2-stage resonance intake 
Hyundai XG V6 - 2-stage variable length manifolds 
Jaguar 3.0 V6 - 3-stage variable length manifolds 
Mercedes V6 and V8 - variable length manifolds, probably 2-stage 
Nissan 3.0 V6 (Maxima), 2.5 inline-6 and V8 - 2-stage variable length manifolds 
Opel 3.2 V6 - 2-stage variable length manifolds 
Peugeot 2.2 four and 3.0 V6 - 2-stage variable length manifolds 
Porsche 996 Carrera / GT3 and all Boxsters - 2-stage resonance intake 
Renault Clio 2.0RS - 2-stage variable length manifolds 
Volkswagen group 1.6-litre four and VR6 - 2-stage variable length manifolds 
Volkswagen W8 - 2-stage resonance intake


----------



## Issam Abed (Feb 12, 2004)

*Re: (rivethead)*

does anyone know where I can source a reliable runner length ---> collector calculator?


----------



## pwnt by pat (Oct 21, 2005)

*Re: (Wizard-of-OD)*

couldn't find it with a quick search but I believe [email protected] posted a link in the 2.0 tech section about intake manifold design with calculations.
This has some fancy math in it though...
http://en.wikipedia.org/wiki/Helmholtz_resonance


----------



## PowerDubs (Jul 22, 2001)

*Re: (pwnt by pat)*

Keep this tread going!! http://****************.com/smile/emthup.gif


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (PowerDubs)*

Has anyone ever messed around with variable runner lengths for the VW 8v or 16v? I'd think the 16v could benefit from it more, as there is probably less port velocity at low RPM's with the 16v head. The 8v's don't seem to have as much potential for a dual length intake.
Does the new 5 cylinder use any sort of variable runners or variable camshaft timing?


----------



## PowerDubs (Jul 22, 2001)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_Has anyone ever messed around with variable runner lengths for the VW 8v or 16v?

About 5-6 years ago I made a hybrid 16v manifold using the larger plenum from a US 42mm (designed for a 2.0) cut and added to the larger 50mm runners on the euro manifold (which was designed for a 1.8 remember). While I was at it I shortened the runner length 1.5 inches.
This was tested on a stock 2.0 block and 2L head with only a euro intake camshaft. The results were very interesting in that allowed the peak HP to be maintained until 7,000 RPM (again stock 2L head, euro cam, stock exhaust manifold). http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I would have loved to been able to test it with larger cams, header, ported head...


----------



## Mortal_Wombat (Jan 29, 2004)

epic thread is epic.


----------



## manfredwerner (Jan 30, 2007)

awesome, i will copy the whole topic.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (PowerDubs)*


_Quote, originally posted by *PowerDubs* »_
About 5-6 years ago I made a hybrid 16v manifold using the larger plenum from a US 42mm (designed for a 2.0) cut and added to the larger 50mm runners on the euro manifold (which was designed for a 1.8 remember). While I was at it I shortened the runner length 1.5 inches.
This was tested on a stock 2.0 block and 2L head with only a euro intake camshaft. The results were very interesting in that allowed the peak HP to be maintained until 7,000 RPM (again stock 2L head, euro cam, stock exhaust manifold).


Thanks for posting this. http://****************.com/smile/emthup.gif 
Definitely a very cool experiment. I've read in the past about the plenum issues with the VW 16v manifolds, and that everyone seems to overlook that fact when going with a 50mm manifold...
When you did this, was it your goal to raise the powerband by shortening the runners?
http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## PowerDubs (Jul 22, 2001)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_When you did this, was it your goal to raise the powerband by shortening the runners?



Yes, within the limits of what I could do and still have the manifold bolt right on to the car as a direct swap.. the dyno is of a standard 50mm upper VS my modified 50mm upper. Only took a few minutes to swap at the dyno.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (PowerDubs)*

Looking back at the dyno graph, It's really interesting to see how what you did affected the powerband.
What is the drop-off at 7300? Is that the fuel cut off?
So, it looks like you dropped a couple Ft/lb. of torque vs. the stock 50mm manifold, but also moved the torque peak up about 400 Rpm. (while raising the torque curve past 5500 Rpm)
The gain in Hp and the curve is cool as well. I think it would be interesting to build a couple different manfolds ranging from a SRI to a long runner manifold (and with combinations of small plenums and large plenums)
and then dyno test them back-to-back to see the changes.



_Modified by Jettaboy1884 at 10:10 AM 1-21-2008_


----------



## 4ePikanini (Aug 29, 2007)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_
Option two would be to find a good stock crank with a shorter stroke that will bolt in place.
Pros: again it is cheap and if it is a forged unit it should be plenty strong
Cons: I am not real sure about VW but most companies don’t build stock forged cranks and if they do they might not have so many engines with different displacements to pick from that will share cranks.


This is only possible by getting longer conrods or thicker pistons to maintain the compression on top. That is if i understand my spatial awareness correctly


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (fourie_marius)*

A couple of great links posted in the sibling thread to this one:
Flow Velocity, Capacity, and Quality
http://www.team-integra.net/se...eID=4
Intake Manifold Runner Size Calculations
http://www.team-integra.net/se...D=466
Exhaust Tech 1
http://www.team-integra.net/se...ID=48
There are many other very informative articles such as these on this page:
http://www.team-integra.net/se...how=1


----------



## Ligero (Jul 17, 2006)

*Re: (Wizard-of-OD)*

I thought you guys might be interested in this manifold design. It is from a Alpina B7 turbo car. It has 3 plenums, the air flows threw the throttle body into the first plenum then from there it splits into 2 runners and flows to 2 separate plenums that each feed 3 cylinders.


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## Jettaboy1884 (Jan 20, 2004)

Nice picture.
That is interesting for sure. I wonder if the two secondary plenums are linked to each other in any way, or if they are independant.
It is also interesting because this is a turbo motor, and I would think that a turbo setup would benefit from the least amount of turns. 
I would also think that the air will loose velocity each time it enters a plenum. In a forced induction motor, I don't understand how having several plenums could be a good thing for the pressurized air...
Any more pictures of that setup would be great, and maybe some details of the engineering aspect behind it. (This would probably be a good question to ask in the FI forum)


----------



## Ligero (Jul 17, 2006)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_Nice picture.
That is interesting for sure. I wonder if the two secondary plenums are linked to each other in any way, or if they are independant.
It is also interesting because this is a turbo motor, and I would think that a turbo setup would benefit from the least amount of turns. 
I would also think that the air will loose velocity each time it enters a plenum. In a forced induction motor, I don't understand how having several plenums could be a good thing for the pressurized air...
Any more pictures of that setup would be great, and maybe some details of the engineering aspect behind it. (This would probably be a good question to ask in the FI forum)

The 2nd plenums were separate from each other and feed 3 cylinders each. I asked the BMY gurus and none of them had any idea why the manifold had 3 plenums they just said Alpina wouldn't have done it if it wasn't good.


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Ligero)*

Well, as much as I trust that they put some serious research into the manifold, I can't go on blind faith and assume that it works better than a simpler intake, just because Alpina says so... (After all, they are catering to enthusiasts with deep pockets)
I'll try to find out more about the setup, as it probably introduces some interesting resonance characteristics to the intake...


----------



## demelok (May 7, 2006)

looks like a intrestin set up, it looks like it might work on paper.... the longer intake tubes.... this set up would be cool on a 16v or aba
btw Keep the tread goin ... i've been lurkin this thread for weeks


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## ny_fam (Apr 3, 2004)

*Re: (Ligero)*

I'd suggest that the three plenums are there so that 1 plenum isn't being used to fill all 6 cylinders. One plenum filling 6 cylinders would have to be very small to take advantage of wave tuning, but not big enough to build density and fill the chambers.
So 3 & 4 cylinders per plenum works out better. Also could be under the hood geometry, They didn't want the runners to be to long, so why not put another plenum in the mix. 
The primary reason to have the plenum is to build density from the air entering the intake track.


----------



## 84_GLI_coupe (Apr 3, 2001)

*Re: (ny_fam)*

More than 4 cylinders per plenum isn't recommended for wave tuning. For 2 cyl's per plenum, volume should be about equal to the volume of the 2 cylinders.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_More than 4 cylinders per plenum isn't recommended for wave tuning. For 2 cyl's per plenum, volume should be about equal to the volume of the 2 cylinders.

I recall reading that for some reason regarding the induction pulses, a plenum feeding three cylinders is ideal... Has anyone else heard of this?
I was reading a great thread on an SHO forum, and the following links were posted to some good articles that are worth reading:
Cylinder Head Porting:
http://en.wikipedia.org/wiki/Cylinder_head_porting
Cylinder Head Porting written by David Vizard:
http://www.popularhotrodding.c....html
Manifold Vaccum:
http://en.wikipedia.org/wiki/Manifold_vacuum
Boundary Layer (Not specific to airflow in an engine):
http://en.wikipedia.org/wiki/Boundary_layer
Laminar Flow (Not specific to airflow in an engine):
http://en.wikipedia.org/wiki/Laminar_flow
Ekman Layer (Not specific to airflow in an engine):
http://en.wikipedia.org/wiki/Ekman_layer
I found this user on Youtube who has a lot of instructional videos about engine components. Many of them are probably common knowledge to us, but some have little tidbits of things I never knew:
http://www.youtube.com/profile_videos?user=n2s&p=r


_Modified by Jettaboy1884 at 10:22 PM 3-8-2008_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

Another Good link:
http://www.iskycams.com/techtips.php


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Bump


----------



## colovw (Aug 27, 2007)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*

I just jumped onto this thread. Some pretty good info here. I didn't dig through all 15 pages yet, but here is a little tidbit about oversquare or square, or undersquare engines and high RPM's. 
The bore size does not have a direct effect on RPM's as stated somewhere in this thread.
The stroke does though.
Also, bore size directly dictates the size of vales the head can use. You need big valves to get big RPM's.
Historically, most of the great engines are of oversquare design because they were designed to meet specs within a sanctioning body.
For instance, the 1969 Camaro had a 302CI engine to meet Trans Am rules, which limited displacement to 305 cubic inches.
So, working within these limits, how do you get a big valve, high RPM engine? With a short stroke (3 inch) and big bore (4 inch).
If you try to stuff valves into a bore that is too small for them you will run into the "shrouding effect," which is not a good thing to have if you want to make big power.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (colovw)*

Those are some very good points regarding the valves.
Thanks for checking out the thread. IMHO, it's worth reading the whole thing, as we've been talking about many different aspects of NA motors. http://****************.com/smile/emthup.gif


----------



## colovw (Aug 27, 2007)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

I definitely will when I get time.


----------



## Jettaboy1884 (Jan 20, 2004)

Bump.
I just got a book about the scientific design of intake and exhaust systems. It's extremely in-depth, but very good so-far!


----------



## mackamitsu (Apr 15, 2008)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Diggatron)*

dry sump is also a nice way to free up HP. It lowers the drag experienced when the lobes splash through the oil. 
not sure on the motor codes but I will agree that the oil squirters make a large difference.
I know of guys running peened rods to 11G for bursts in races with no ill effects. Its a 1.3l mazda motor too.


----------



## Issam Abed (Feb 12, 2004)

*Re: (Jettaboy1884)*

Ok the cats out the bag
http://forums.vwvortex.com/zerothread?id=3875552


----------



## PowerDubs (Jul 22, 2001)

*Re: (Wizard-of-OD)*

Ported R32 head is done
http://forums.vwvortex.com/zerothread?id=3831647


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (PowerDubs)*

Awesome! Looks like some very top-quality work. http://****************.com/smile/emthup.gif 
I'm diggin the knife edged valve guides. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## mk3house (Mar 28, 2008)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

....good lookin out meng....very useful info....


----------



## ny_fam (Apr 3, 2004)

*Re: (PowerDubs)*

Agreed, very nice work.
I assume that will be installed on a full R32 setup. Anyone have technical data on the intake system for the R?


----------



## vwpat (Oct 25, 2000)

*Re: (ny_fam)*

another crank option is the late euro 1.6 that has a 77.4 mm stroke and has large rod journals so it can use 1.8 or 2.0 rods. Unfortunately most if not all are cast but so are most of the late cranks so may not be that much of a negative. 1.8 rods are 144 mm not 146. Bertils used to have "spacer" rod bearings that would allow 1.8 rods on 1.6 cranks but have not seen them in years.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwpat)*


_Quote, originally posted by *vwpat* »_another crank option is the late euro 1.6 that has a 77.4 mm stroke and has large rod journals so it can use 1.8 or 2.0 rods. Unfortunately most if not all are cast but so are most of the late cranks so may not be that much of a negative. 1.8 rods are 144 mm not 146. Bertils used to have "spacer" rod bearings that would allow 1.8 rods on 1.6 cranks but have not seen them in years. 

I am very interested to look into this more. I'm looking for an OEM way to build an oversquare bottom end. This is definitely news to me!
Thanks.


----------



## vwpat (Oct 25, 2000)

*Re: (Jettaboy1884)*

1595cc, 8v, 81 X 77.4, 9:1 IIRC, used 1.8 block, rods, etc. There are factory 16V pistons available from the French market Audi 2.0 20V.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwpat)*

Sweet. I'll keep my eyes out for any of this Europian market stuff!
No news from me. I've been reading some good books, but that's about it for now. http://****************.com/smile/emthup.gif


----------



## polov8 (Apr 14, 2004)

*Re: (Jettaboy1884)*

I have one of these cranks. anyone interested????


----------



## Issam Abed (Feb 12, 2004)

*Re: (Ligero)*


_Quote, originally posted by *Ligero* »_I thought you guys might be interested in this manifold design. It is from a Alpina B7 turbo car. It has 3 plenums, the air flows threw the throttle body into the first plenum then from there it splits into 2 runners and flows to 2 separate plenums that each feed 3 cylinders.


They did all kinds of weird things in the early days.I bet a straight through plenum did a better job.


----------



## LT1M21Stingray (Sep 14, 2006)

*Re: (polov8)*

Subscribed. http://****************.com/smile/emthup.gif


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Mtl-Marc)*

Can anyone post up pictures or drawings of intake and exhaust ports that flow very well?
Not sure if I posted this up earlier, but here is a great site where the guy experiments with some interesting results.
http://www.cmc.net/~xero/Mousesporting.html
I was surprised to read that an intake port that aims straight at the valve is not necessarily the best flowing.
Has anyone ever taken a mould of their port?


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

Does anyone have some information about calculating the taper of an intake port?
I'm also looking for any info about tapered ports, vs. ports that have a consistent diameter from the valve to the plenum. All the info I have read says that a slight port taper will help increase airflow.
Mike.


----------



## elveloz69 (Aug 26, 2006)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

wow http://****************.com/smile/emthup.gif


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

Well, let's raise this back from the dead.
I just found out that I'm going to be building another VW 8v motor, and I've been doing a ton of reading about intake manifold design. (And yes, I know the intake manifold isn't the major limiting factor on an 8v motor)
I came across an excellent thread in a Miata forum, with a bunch of great links about intake manifold design. A bunch of them are geared towards forced induction, but plenty are for NA setups.
Here's a link to the thread. There are great links on Pg. 2 and I'll post these links individually once I have a little extra time. http://****************.com/smile/emthup.gif 
http://forum.miata.net/vb/show...pp=25


----------



## notso2slo (May 1, 2006)

Has anyone ever made an intake with adjustable dimentions?
I'm thinking about doing this. It would be perfect for testing the best combo of runner length and plenum volume.


----------



## bobsled (Aug 25, 2006)

*Re: (notso2slo)*


_Quote, originally posted by *notso2slo* »_Has anyone ever made an intake with adjustable dimentions?
I'm thinking about doing this. It would be perfect for testing the best combo of runner length and plenum volume.

in the link in the post above yours i think there was a picture of one but im not sure. seals and gaskets would be an issue. 
also have to take into account the added turbulence from the adjustable pieces. in other words. it would be a good way to compare from one plenum/runner dimension to another, but may not yield accurate results when the actual manifold is fabbed.
edit: this is simplified from what you mentioned, but still pretty cool: http://www.hpamotorsports.com/cvp.htm


_Modified by bobsled at 3:24 AM 10-14-2008_


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## notso2slo (May 1, 2006)

Well, I was thinking of using a sort of sleeve system. Use a larger tube over the actual runners, so you could just add or remove a section of pipe to change the runner length. And for testing purposes, it wouldn't be that hard to tape it sealed, since it doesn't have to last more than a couple dyno runs. But you're still right, it would definitely yield different results than a finished product, but it would be close enough to fine tune runner and plenum size.


----------



## vwpat (Oct 25, 2000)

*Re: (notso2slo)*

some of the world challenge cars (esp. the Mazdas) use adjustable inlet manifolds that are connected with silicone couplers. I guess to vary it for different tracks.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (vwpat)*

I recall a Mazda motor that had variable length intake runners on a rotary. A google search shows it as the R26B motor, which powered the 787B racecar.
I recall seeing a video on youtube that showed them in action, but I can't find it yet...


_Modified by Jettaboy1884 at 10:50 PM 10-14-2008_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

BTW, I came across this program where you can build an engine and do all sorts of performance modifications to it, and see how it will react to each.
Unfourtinitely, the program is $350.00








Link: http://www.motionsoftware.com/Dynomation5.htm


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

I'm a big fan of articles written by David Vizard. A lot of his articles are fairly dated, but most of the information is still applicable.
A good 3-page article by Vizard about Rods, Pistons, and Crank Angles:
http://www.popularhotrodding.c....html



_Modified by Jettaboy1884 at 12:30 AM 10-16-2008_


----------



## PowerDubs (Jul 22, 2001)

*Re: (Jettaboy1884)*

Whoever is still watching this thread- check my sig!! http://****************.com/smile/emthup.gif


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## Jettaboy1884 (Jan 20, 2004)

*Re: (PowerDubs)*


_Quote, originally posted by *PowerDubs* »_Whoever is still watching this thread- check my sig!! http://****************.com/smile/emthup.gif 

Heck Yeah!!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


----------



## wantacad (Apr 4, 2003)

*Re: (Jettaboy1884)*

subscribed..


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## herby53-akaherby53 (Dec 24, 2003)

*Re: (wantacad)*

mike , been a few years ( over 4 ) . i just read the whole thread in one sitting . love it . bump for a great thread i will keep reading. 
i am building another N/A high compression 8v right now and this has me thinking about the 1.6 cranks.


----------



## kenny_blankenship (Feb 19, 2005)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_I recall a Mazda motor that had variable length intake runners on a rotary. A google search shows it as the R26B motor, which powered the 787B racecar.

WRONG. the 787b was powered by a 4-rotor "26B" engine. the RB26 is a nissan skyline motor (short for the engine code of RB26DETT)


----------



## Issam Abed (Feb 12, 2004)

*Re: (kenny_blankenship)*


_Quote, originally posted by *kenny_blankenship* »_
WRONG. the 787b was powered by a 4-rotor "26B" engine. the RB26 is a nissan skyline motor (short for the engine code of RB26DETT)


*WRONG*
http://www.geocities.com/fdkaimember/r26b.html


----------



## XXX008XXX (Mar 26, 2002)

*Re: (Wizard-of-OD)*


_Quote, originally posted by *Wizard-of-OD* »_
*WRONG*
http://www.geocities.com/fdkaimember/r26b.html

Issam is on the left...


----------



## EL DRIFTO (Jul 11, 2004)

*Re: (XXX008XXX)*

subscribed


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## shannonekermans (Oct 9, 2007)

i know this may be a little closer to the begin of this discussion, but could someone please explain how much compression affects performance, ie is there a direct relationship between compression and horsepower as explained in the article about adding 1/10th intake of oxygen due to the extra compression? 
by the way this is a awesome thread


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*

Hp increase percentage is relevant to what your current compression is to where you plan on raising it to. In other words, you would have a greater percentage of hp gained if you went from 9:1 to 12:1, than if you went from 11:1 to 13:1.
This graph kinda-sorta is a visual for that


----------



## shannonekermans (Oct 9, 2007)

so its inverse, no reason to run extreme compression, but every little bit helps in creating these high hp 8vs thanks thats really helpful i do have another question, earlier a guy mentione running 36mm intake and 34mm exhaust valves, has this got any effect on where the powerband lies on the motor as well as wouldnt the relatively smaller exhaust port in comparison to the intake cause the exhaust gasses to be left in the chamber while fresh air is being fed in or does that only make a difference on the amount of overlap the cam has?
thanks


----------



## Tom A (Oct 20, 2004)

*Re: (shannonekermans)*

Inverse? It isn't linear, in that increasing the compression by a given amount will not always give you the same increase in power.
That graph is a little confusing, the lower axis is labeled differently that other versions of the same chart I have seen. Each number on the lower edge should be a 1 point increase. In that chart where it says 9:1, it should say 8:1 to 9:1, meaning if you go from 8:1 to 9:1 compression, you should get a 1.8% increase in power.
The larger advantage of increasing compression is to try and offset some of the dynamic compression loss of running a hotter cam.
For example, I ran the numbers a while back for a stock 1.8 A1 GTI:
Stock static compression ratio: 8.5:1
Dynamic compression ratio with the stock cam 7.42:1
Dynamic compression ratio with a Elgin 308º cam 6.18:1
To get the dynamic compression back to the stock level with that cam, you would need to start at ~10.5:1.
-----------------------
I also found an excellent 10 part series on head porting by David Vizard:
http://www.gofastnews.com/boar....html


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (tdogg74)*


_Quote, originally posted by *tdogg74* »_Hp increase percentage is relevant to what your current compression is to where you plan on raising it to. In other words, you would have a greater percentage of hp gained if you went from 9:1 to 12:1, than if you went from 11:1 to 13:1.


It's funny that this question about compression came up. I could swear that just a day or two ago, I saw a good chart that shows a percentage increase in power, as you raise compression. As you raise compression, the power increase becomes less and less, until there is a negligible increase from going to (IE 13:1 to 14:1.
I'll see if I can find that chart. http://****************.com/smile/emthup.gif


----------



## shannonekermans (Oct 9, 2007)

excuse me for not being as knowledgeadble as you guys but how do the differences in static and dynamic compression make a difference? would dynamic compression be more useful than static, or is it that static compression is a baseline while dynamic is a variable that is determined by the components of the motor itself ie (pistons operating temprature etc)


----------



## Tom A (Oct 20, 2004)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_excuse me for not being as knowledgeadble as you guys but how do the differences in static and dynamic compression make a difference? would dynamic compression be more useful than static, or is it that static compression is a baseline while dynamic is a variable that is determined by the components of the motor itself ie (pistons operating temprature etc) 

Good writeup here:
http://www.empirenet.com/pkelley2/DynamicCR.html


----------



## shannonekermans (Oct 9, 2007)

so by running a larger overlap cam you are dropping the DCr which then has a loss in hp as explained by the graph above but allows for better cylinder fill and therefore a gain in combustion capability?


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## shannonekermans (Oct 9, 2007)

well yes it does explain it, a little more in depth than i understood but it all makes sense thanks 
the more info the better


----------



## Tom A (Oct 20, 2004)

*Re: (shannonekermans)*

I just noticed Wikipedia has a pretty good explanation as well.
http://en.wikipedia.org/wiki/Compression_ratio
Here is the Readers Digest condensed version:
Compression ratio is the ratio of the volume of the cylinder when it is at the bottom of the stroke, to the volume at the top of the stroke. This is the static compression ratio.
The problem is that the intake valve is not closed when the piston starts the compression stroke, so pressure can escape back out the valve. This is Dynamic compression. As the intake duration of the cam increases, the intake valve closes later in the compression stroke, making less of the stroke available to compress the charge.
Reducing the compression ratio naturally lowers power, in the case of the A1 GTI above switching from the stock cam to the Elgin G-prod cam drops the dynamic compression ~1.3 points, and in theory should reduce the available power by ~2% (guessing based on the chart above).
You wouldn't notice the drop, because the increase in power from the ability of the engine to flow more air from the camshaft will more than make up for the drop in power from compression, and the engine should still make more power overall, assuming that the head/intake/exhaust can flow enough air and there is enough fuel to support it.
Clear as mud?









On Edit:
Another article, this time from David Vizard/Popular Hot Rodding:
http://www.popularhotrodding.c....html


_Modified by Tom A at 2:43 PM 1-10-2009_


----------



## redGTInj (Jul 6, 2003)

*Re: (Tom A)*

awesome thread and read!
i've applied alot of the thoughts and ideas to my personal motor....I finally have access to a computer alot now, so I will be in here alot..


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## Jettaboy1884 (Jan 20, 2004)

*Re: (redGTInj)*

I'm stoked to see this discussion pick up again.
That Vizard article is excellent, and I'll have to read it over and over to absorb it all. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
I'm also reading through the compression ratio stuff, as it was something I never fully understood. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
On a side note: I drove a Cabriolet with a fully balanced 2.0L 8v & Eurospec head the other day. I was so impressed with the difference that a balanced bottom end makes! The motor was butter smooth, and really woke up from 4000-6500 Rpm.
I was thinking about cam timing recently, and am wondering if anyone can give their thoughts on how: Cam duration, timing, port size, and overall port length, _combine_ with each other to affect the powerband.


----------



## redGTInj (Jul 6, 2003)

*Re: (Jettaboy1884)*

whats up jettaboy i think you posted on my thread a while back...
i got my N/A 16v gti CIS-e
dynoed again like 2 weeks ago, its a new motor, with only about 1,000 miles on it..figured i go and get a baseline, with what I'm working with...
















and of course a video!!!

i chose to say with the 9a.....instead of going to the taller ABA with longer rods...I built this motor to rev...my last motor which was also a 9a, would regularly see 8,000...that motor made 160WHp
once this new motor is broken in i will be going back... of course with some new goodies which i will post soon...
i've tried a few differnt things, and have gotten some pretty good results, from the velocity stack in the grill, to overbore throttle body, to upgraded ignition system while only using one kind of spark plug which works excellent....
all this was with a 2.25" exhaust....I will hopefulyy be going back soon with a 2.5"...what do you guys think?


----------



## redGTInj (Jul 6, 2003)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_ I was so impressed with the difference that a balanced bottom end makes! The motor was butter smooth, and really woke up from 4000-6500 Rpm.
.

excellent point, with my new motor i'm running now, I had all rotating parts balanced in the bottom end including the crank pulley, pressure plate & flywheel, and am running an scch lightened balanced intermediate shaft.....
with all the balancing, and the fact that 
crank pulley
PS pulley 
WP pulley
alt pulley
intermediate gear
cam gear
flywheel
are ALL lightened, it makes for a VERY smooth and fast revving engine...i know some people, arent for lightened components, but for me it's worked out http://****************.com/smile/emthup.gif


----------



## redGTInj (Jul 6, 2003)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
I was thinking about cam timing recently, and am wondering if anyone can give their thoughts on how: Cam duration, timing, port size, and overall port length, _combine_ with each other to affect the powerband.

i'll defentely be into hearing what you guys have to say about cam timing....what i seen and done between my last two motors has been quite interesting especially with cam timing...
like i said before, my last motor made 160whp before and the new motor so far has made 172...i went to the same dyno, and kept the SAME cams....
i did however increase the bore to 83.5, put oversized Intake valves, exhaust were already installed on first dyno, and I have a TT race header now, where previously was an atutotech street header...and the TB was stock, where now is overbored 4mm
on the 160WHP run I ended up advancing cam timing, about 3 degrees, moving the power band down a little and where the cams start coming on...at this time i was only revving to the stock 7,200 rpm limit as i did not have the means to go up higher...by advancing the cam timing there was hp being gained with every degree of advancing, it also couldve been the ignition timing being adavanced as well, which happens on a 16v cause the gear is connected the the exhasut cam which runs the rotor in the dizzy....
now the point which i sort of wanted to make, is that on the 172whp run I did not touch cam timing at all, and was left at the 0 position...just by letting the engine breath more, i was able to utilize the cams better, without having to start the power band earlier...the peak did move up 200rpm, but thats fine as u can see the motor was still making power but i did not want to push it more, since it's soo new...
on the car now, u can really feel the power come on at 5k and it just pulls nasty after that...
when leaving the cams at zero on the first dyno, it made less than 160...just interesting that it made already 12whp more without adjusting them....


----------



## 75injectedSB (Feb 6, 2006)

*Re: (redGTInj)*


_Quote, originally posted by *redGTInj* »_
i'll defentely be into hearing what you guys have to say about cam timing....what i seen and done between my last two motors has been quite interesting especially with cam timing...
like i said before, my last motor made 160whp before and the new motor so far has made 172...i went to the same dyno, and kept the SAME cams....
i did however increase the bore to 83.5, put oversized Intake valves, exhaust were already installed on first dyno, and I have a TT race header now, where previously was an atutotech street header...and the TB was stock, where now is overbored 4mm
on the 160WHP run I ended up advancing cam timing, about 3 degrees, moving the power band down a little and where the cams start coming on...at this time i was only revving to the stock 7,200 rpm limit as i did not have the means to go up higher...by advancing the cam timing there was hp being gained with every degree of advancing, it also couldve been the ignition timing being adavanced as well, which happens on a 16v cause the gear is connected the the exhasut cam which runs the rotor in the dizzy....
now the point which i sort of wanted to make, is that on the 172whp run I did not touch cam timing at all, and was left at the 0 position...just by letting the engine breath more, i was able to utilize the cams better, without having to start the power band earlier...the peak did move up 200rpm, but thats fine as u can see the motor was still making power but i did not want to push it more, since it's soo new...
on the car now, u can really feel the power come on at 5k and it just pulls nasty after that...
when leaving the cams at zero on the first dyno, it made less than 160...just interesting that it made already 12whp more without adjusting them....


Great info man, and great info in the whole thread. I have a build coming up and I have been living in the NA forum, gathering all I can. I will be staying CIS as well, hope I can make it up to where you are. You are the benchmark, lets see how close I can get...
Keep up the great work guys...


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## EL DRIFTO (Jul 11, 2004)

*Re: (75injectedSB)*

i love cis


----------



## nick526 (Sep 29, 2006)

*Re: (EL DRIFTO)*

Let's talk flow bench testing for a minute. 
Is the head tested fully assembled (valves, cams, etc) or bare? With or without manifolds or both? I see a lot of articles about cam selection mention that the cam should match up with the cfm of the head but if the head is flow tested with the cam(s) installed isn't it kind of a catch 22? 
What type of cfm numbers would one expect out of the various vw heads out there, stock and/or with headwork, big valves etc.
Does anyone watching this topic frequently work with a flow bench? I'd love to hear some tech talk on the topic from a pro, or even a skilled amature.


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## Tom A (Oct 20, 2004)

*Re: (nick526)*

Never done it, but the process is fairly well known. Generally speaking, (and I am sure this can vary a little bit depending on flow bench design and preference)
The head should be assembled, minus the cam and using a vary weak spring. a 'Manifold" of sorts is used to smooth the airflow into and out of the ports. This could be a simple as hand molded clay, or a custom piece designed to match a specific head.
A fixture is used with a dial indicator, and the flow is measured at various lifts.
Here is a photo showing the clay method:
http://images.circletrack.com/...g.jpg

_Quote, originally posted by *nick526* »_ I see a lot of articles about cam selection mention that the cam should match up with the cfm of the head

What people are getting at is that if your head doesn't flow any more at .45 lift than it does at .40, having a cam with the extra lift doesn't do anything for you.
There are some numbers in the Vizard DIY porting article, it is online here:
http://forums.vwvortex.com/zerothread?id=3505069


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## ny_fam (Apr 3, 2004)

*Re: (Tom A)*

To add to this -
Standard methods as mentioned above don't include the manifold/ITBs or carbs.
Some of the testing of the intake tract "should" include the manifold. I've seen a few VW performance developers test the head as mentioned above, then test with the intake attached to see where the restriction has moved to, and at what lift(as I do). Head flow numbers are great for comparing work etc.. but head with intake attached gives a better picture of how they will perform together.
Also to note: Flow differences between ports is important. as most fuel injection systems don't meter fuel for each cylinder individually. So a port that flows 5% less than the others is getting to much fuel, or port that flow 5% more than the others is not getting enough. the only place (other than my tests) I've seen produce flow # for all the ports is SCCH. Flow differences cause broken pistons in boosted engines.
ny_fam


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## Jettaboy1884 (Jan 20, 2004)

*Re: (ny_fam)*

Here's a good article:
http://www.elgincams.com/campaper.html
And another:
http://speedtalk.com/forum/viewtopic.php?t=840


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## shannonekermans (Oct 9, 2007)

while we on this subject of headflow would anyone like to elaborate on the 8v head, counterflow vs crossflow, if the same extensive work had been done on both ( ie port polish, same cam both larger valves etc) would they the crossflow yield better results? i have heard stories of either one being just as good?


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_while we on this subject of headflow would anyone like to elaborate on the 8v head, counterflow vs crossflow, if the same extensive work had been done on both ( ie port polish, same cam both larger valves etc) would they the crossflow yield better results? i have heard stories of either one being just as good?

It is my understanding that the counterflow has slightly more potential for flow than the crossflow. I have heard that Colin at TT shares this line of thought, for the reasons below:
Here are a couple cutaways of each:
Crossflow Intake Port. Note the fairly "low" port angle of approach, and the sharp short side radius. From this angle, it almost looks like the air would want to flow across the valve head, and tumble into the cylinder (like a 16v), which is not the inherent trait in two valve heads.









Counterflow Intake Port. Compared to the Crossflow, note the slightly higher approach, and how the throat above the valve seat has more vertical distance before turning on the short side. Also note how the bowl has significantly more area just after (to the left of) the valve stem. These are traits of a swirl port, which is typical of two valve heads.









Here are the exhaust ports of both heads. They are quite similar. It is important to note that the exhaust port does not flow quite enough to reach the desired ~70% CFM of the intake port. 
Counterflow:









Crossflow:









These are my observations of the ports, which I obtained mostly through reading and poking around in some spare heads...
I'll leave it up to Derek, or someone else to comment on the real world airflow of these, as I don't have the experience.


_Modified by Jettaboy1884 at 8:34 AM 1-22-2009_


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## shannonekermans (Oct 9, 2007)

i have no experience here and this is why i ask as it seems like the counterflow has much more restrictions in the port compared to the counterflow, but you speak of tumble and swirl, i am correct in saying that swirl is better for a 8v head? if you have info i could read etc a link that might explain i would really appreciate it. thanks


----------



## jackfrost1031 (Oct 19, 2004)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_...it seems like the counterflow has much more restrictions in the port compared to the counterflow...

Are you basing this on the valve guide boss? Keep in mind that that it doesn't block as much as you might think. The port angle means more.


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_i have no experience here and this is why i ask as it seems like the counterflow has much more restrictions in the port compared to the counterflow, but you speak of tumble and swirl, i am correct in saying that swirl is better for a 8v head? if you have info i could read etc a link that might explain i would really appreciate it. thanks

I believe this link is somewhere in this thread, but here you go:
http://www.popularhotrodding.c....html
This is an excellent article by David Vizard about cylinder head design. It's pretty straightforward, but each time I re-read it, I learn a bit more. http://****************.com/smile/emthup.gif


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## shannonekermans (Oct 9, 2007)

that article is great, its a little to advanced for me right now but im picking it up slowly and will have it soon.
thanks


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## CCCylinderheads (May 6, 2008)

*Re: (jackfrost1031)*


_Quote, originally posted by *jackfrost1031* »_Are you basing this on the valve guide boss? Keep in mind that that it doesn't block as much as you might think. The port angle means more.

Port angle is important, but that guide and boss hanging in the breeze never helps anything. On HONDA heads, I see 10 cfm from knocking them out of there. The crossflow EXH port "looks" nice, with a nice long, bowl/throat area before the guide. but that is wasted inertia on a EXH port, you want the gas out as quickly as possible. The 16V has less bowl volume, and overall port length looks shorter as well. Get old gas out quickly, get new gas in quickly, make HP.


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## Jettaboy1884 (Jan 20, 2004)

*Re: (CCCylinderheads)*

Bump back up.


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## elmer fud (Aug 5, 2003)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_while we on this subject of headflow would anyone like to elaborate on the 8v head, counterflow vs crossflow, if the same extensive work had been done on both ( ie port polish, same cam both larger valves etc) would they the crossflow yield better results? i have heard stories of either one being just as good?

I was once on the crossflow side of the pond. but I have been doing lots (realy like 2 weeks of unemployment) resurch in all porting. and I believe the counter flow is better in all ways but one..... the heat of the exhust heating up the intake, but this is really not as big of a deal as you might expect. some heat shields and some metal coating can make it a non issue .

the aba in stock form is better, but once ported and cleaned up a good counterflow gti big valve head is better then a crossflow..... and then add on the fact you can get it in stock form in solid lifter that just put's a step ahead in for those looking for serious power .
it is very eye opening for me and has changed my veiw on the aba head. 
P.S. jodi you were right all along. lol

__
Image uploading. Refresh page to view













_Modified by elmer fud at 7:07 PM 2-21-2009_


----------



## shannonekermans (Oct 9, 2007)

so what type of heat treating methods, cause ill be building a big valve 8v motor and would like to port etc and was wandering what would be best. ill be going 42/35 and stage 3 head work


----------



## elmer fud (Aug 5, 2003)

*FV-QR*


_Quote, originally posted by *shannonekermans* »_so what type of heat treating methods, cause ill be building a big valve 8v motor and would like to port etc and was wandering what would be best. ill be going 42/35 and stage 3 head work


I don't know what your asking I said nothing about heat treating, what do you want to treat? 
and when you say 42/35 are you talking carb. my yellow bunny has a 32/36 and that works great, I would think a 38/36 would cover all 8v street motors, and my 32/36 works well enough I would think it would be best foe most applications. 


_Modified by elmer fud at 12:14 AM 2-22-2009_


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## shannonekermans (Oct 9, 2007)

my apologies, what type of metal coatings or heat shields are you refering to. and i was talking about valve sizes for the counterflow head 42mm/ 35mm.


----------



## elmer fud (Aug 5, 2003)

*FV-QR*

I wasin't ...lol I was saying that one advantage over the counterflow head is that the crossflows intake being on the ft does not get heated up by the exhaust, but like I said this is not enough of a advantage to make it better then the counterflow.


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (elmer fud)*

the flow differences between the counter and cross flow heads are way more significant than heat transfer could ever be
the pictures on pg6 are the icing
out of the archives for my question too:
i keep hearing that the ideal squish is .05". which means 16v 2.0 head gasket only for 2.0 aba counterflow.
it seems like corky bell claimed generically .03? so...
some years ago before i had internet, i didn't know so i was using the short one for 2 years no problems. 
195 psi on the compression tester, 15 psi sc, 99 octane (xylene enhanced)
has someone tried the short gasket and failed already somewhere?


----------



## elmer fud (Aug 5, 2003)

*FV-QR*


_Quote, originally posted by *EL DRIFTO* »_the flow differences between the counter and cross flow heads are way more significant than heat transfer could ever be
the pictures on pg6 are the icing
out of the archives for my question too:
i keep hearing that the ideal squish is .05". which means 16v 2.0 head gasket only for 2.0 aba counterflow.
it seems like corky bell claimed generically .03? so...
some years ago before i had internet, i didn't know so i was using the short one for 2 years no problems. 
195 psi on the compression tester, 15 psi sc, 99 octane (xylene enhanced)
has someone tried the short gasket and failed already somewhere?










two questions, 
one just to get it streiaght your saying the 16v gaskets squish is .03 on aba block and a 8v head, compared to the .07 of a aba gasket. and that ideal squish is .05 ?
I have heard that ideal squish is as tight as you can go with out hitting. what was your CR and what was your set up, soild head vs. hydro, was it shaven ect.
two can you explane "xylene enhanced" for me, I remeber a thread on it along time ago, and I passed it off cus my thinking was I wont run enough CR to need it..... well now I do, lol what do you buy and how much do you add.


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (elmer fud)*

well i've seen it said somewhere that one has to use a certain head gasket when putting a counter flow head on an aba block or the compression becomes too high. (what i had for 2 yrs)
i used to use xylene:
118 octane, highest btus
5 gallons at wholesale paint supply
i used 1/4 xylene, 93 gas = 99 octane
i tested it with gasoline in various blended containers over 6 months, and the gasoline seemed to soften the rubber more...
edit: they told me to add a capful of ATF per gallon
actually has so many btus it makes lean systems rich enough
now i use e85
105 octane, least btus except for methanol
20% le$$ than gas
2/3 e, 87 gas = 99 octane
DONT put it in anything 1985 or earlier!
burns so slow, even when it preignites, it doesn't detonate


_Modified by EL DRIFTO at 6:09 AM 2-24-2009_


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## elmer fud (Aug 5, 2003)

*FV-QR*


_Quote, originally posted by *EL DRIFTO* »_well i've seen it said somewhere that one has to use a certain head gasket when putting a counter flow head on an aba block or the compression becomes too high. (what i had for 2 yrs)

i tested it with gasoline in various blended containers over 6 months, and the gasoline seemed to soften the rubber more...



not a good canadate for my yellow bunny then cus some num nuts conveted it to ruber hose from the tank to the pump...... oh ya its carberated to the pump is on the block.


----------



## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (elmer fud)*

Government law mandated that everything be ethanol compatible beginning in 1986.
So I wouldn't expect any problems if your components were made in the last 20 years.
Also, I meant that fuel injection hose sitting in a can of straight gasoline got softer, softer than hose sitting in straight xylene or mixes. I should also mention that when detonation or lean goes wrong on xylene, there's way more damage...


_Modified by EL DRIFTO at 2:13 AM 2-26-2009_


----------



## elmer fud (Aug 5, 2003)

*FV-QR*

I was kinda joking ... but kinda not. the bunny is a 1980. and the hose looks to be el-cheepo. but it has held up so far. 
thats a bit more then I would have expected, did you have to adjust timing to run on it?


_Modified by elmer fud at 8:41 PM 2-27-2009_


----------



## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (elmer fud)*

e85 seems to need more timing
edit: xylene will make your car 2 mph faster in the quarter
(even if it's already rich enough and you have the ability to lean it out for xylene)

_Modified by EL DRIFTO at 5:53 AM 3-19-2009_
e85 clicky


_Modified by EL DRIFTO at 10:41 AM 4-2-2009_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (EL DRIFTO)*

I want to bump this back up. I have a few more questions and thoughts, but need to organize myself first... I just dont want this to fall away again. http://****************.com/smile/emthup.gif 
In the meantime, here's a good article about crankshafts:
http://www.circletrack.com/dri....html


_Modified by Jettaboy1884 at 7:51 PM 4-4-2009_


----------



## ramdmc (Jul 25, 2005)

*USF3 Dyno results*

Great thread guys, I've always been a fan on the 8v, an underdog to some.
Which brings me to this... I purchased a couple of the USF3 long blocks approx a year ago and just managed to get a dyno from Bertil Sollenskog. 


I thought you may want to see what kind of numbers it's putting down and at what RPM, who said 8Vs can't spin?



Proof is in the pudding....Dyno sheet.
Sad to see one go, but what do I need with 2 of these?
RC



_Modified by ramdmc at 11:28 PM 4-13-2009_


----------



## nick526 (Sep 29, 2006)

*Re: USF3 Dyno results (ramdmc)*

impressive numbers. any info on those motors?


----------



## ramdmc (Jul 25, 2005)

*Re: USF3 Dyno results (nick526)*


_Quote, originally posted by *nick526* »_impressive numbers. any *info* on those motors?

*Info* can be pretty broad, be specific and I'll do my best


----------



## ny_fam (Apr 3, 2004)

*Re: USF3 Dyno results (ramdmc)*

Specifically Here is what I'd like to know.
how long is the runner from heat to end of trumpet?
is their a restrictor in the runner - like a tapered section?
cam specs duration and lift
head converted to solid lifter?
where is the bottom of the graph? 1800 rpms to 4500 would be interesting.
also like to see the crank used.


_Modified by ny_fam at 2:28 AM 4-15-2009_


----------



## vwpat (Oct 25, 2000)

*Re: USF3 Dyno results (ny_fam)*

http://mikegonos.net/port/usf3/about_engine.html
in french but has info: http://forums.montrealracing.c....html


----------



## ramdmc (Jul 25, 2005)

*Re: USF3 Dyno results (ny_fam)*


_Quote, originally posted by *ny_fam* »_Specifically Here is what I'd like to know.
how long is the runner from heat to end of trumpet?


Will measure tomorrow

_Quote, originally posted by *ny_fam* »_
is their a restrictor in the runner - like a tapered section?


I can't recall, will measure and maybe take photos tomorrow

_Quote, originally posted by *ny_fam* »_
cam specs duration and lift


Custom BRS profile, 300-305ish

_Quote, originally posted by *ny_fam* »_
head converted to solid lifter?


Yes

_Quote, originally posted by *ny_fam* »_
where is the bottom of the graph? 1800 rpms to 4500 would be interesting.


I do not know, but plan to make some alterations and redyno so will have a more accurate wheel hp figure

_Quote, originally posted by *ny_fam* »_
also like to see the crank used.


Crank, knife edged, polished and balanced.
Rods, Carrillo, polished and balanced.
Pistons, 12.4:1, Wiseco forged 
_Modified by ny_fam at 2:28 AM 4-15-2009_[/QUOTE]


----------



## MkIIRoc (Feb 20, 2005)

Now I really have to dyno my new setup. I think I might be able to barely beat that out with carburetion and a counterflow head. I know my power peaks a bit higher. That thing makes good power down low though. Mine is a dog below 5000 rpm. My engine modeler put me at 199 @8250 crank. I do have higher compression and a lower engine life expectancy though.










_Modified by MkIIRoc at 9:35 PM 4-14-2009_


----------



## MkIIRoc (Feb 20, 2005)

*Re: (MkIIRoc)*

Here's another head cross section, it's the first head I ported. Made decent power, but needs some work. (Especially now, has a leak I can't narrow down, haha)


----------



## EL DRIFTO (Jul 11, 2004)

*Re: (MkIIRoc)*

now i'm looking at bertils
something faster than bertils
trumpet dims coming
one of my fav threads http://****************.com/smile/emthup.gif 
grabs bowl (area around valve)


----------



## ny_fam (Apr 3, 2004)

*Re: (MkIIRoc)*

Port Velocity "could" be a major reason why the two peak in different places, and with different low end power. Though this could be the counterflow vs. crossflow factor. Take a look at the power curve for the formula super vee dyno chart
http://www.scientificrabbit.com/node/5
and the SCCA dyno for a all out 1.5 vw racer .
http://www.scientificrabbit.com/node/1


----------



## billyVR6 (May 8, 2000)

*Re: USF3 Dyno results (ramdmc)*


_Quote, originally posted by *ramdmc* »_USF3 long blocks

I was looking the header that Bertil’s uses on these a while back for my “F’ BOTI” race project that I abandoned. I think I may still have some images of one them on my drive at home.
12.5:1 compression ratio is great; many will claim you need something ridiculous like 27:1 to see those numbers. That compression with the 7200rpm peak power is a very realistic engine. It looks like the torque under the curve would be no worse than stock (if not better), making this a hot street engine. I would love to see what this lengine would do with more common parts, like a TT race header and a wet sump.
Sorry if I missed this, but is this one of his 85mm bore engines, and was this run on pump or race gas? 
Thanks.


----------



## EL DRIFTO (Jul 11, 2004)

*Re: (ny_fam)*

interesting how the intake flutes are reversed, slowing down for the butterfly there ny fam
like old jags i've seen


----------



## ny_fam (Apr 3, 2004)

*Re: (EL DRIFTO)*

I think thats the placement for the 32mm restrictor (referring to the FSV intake on my site). Though I thought the restrictor was was just before the throttle plates. 
The restrictor was part of the racing rules, and is still part of the historic racing class maintained by http://www.monoposto.com/


_Modified by ny_fam at 12:48 PM 4-16-2009_


----------



## secondgen (Jan 9, 2004)

*Re: (MkIIRoc)*


_Quote, originally posted by *MkIIRoc* »_Here's another head cross section, it's the first head I ported. Made decent power, but needs some work. (Especially now, has a leak I can't narrow down, haha)

When you say "decent power" do you have a number representation or just a seat of the pants power reader?


----------



## MkIIRoc (Feb 20, 2005)

*Re: (secondgen)*

Seat of the pants. It was on the dyno, but the box locked up. I don't know how mustang dyno's work, but he said it didn't get any power numbers from the run. They said they have to set the start and end points in mph then run it for a pass. Didn't make much sense to me, but that was close to 4 years ago, don't remember the details.
Only ever ran on a dynojet after that, and you just hit a button and watch the screen.
Picture was just for reference, not a "this is how to port a head", haha.


----------



## secondgen (Jan 9, 2004)

*Re: (MkIIRoc)*


_Quote, originally posted by *MkIIRoc* »_Seat of the pants. It was on the dyno, but the box locked up. I don't know how mustang dyno's work, but he said it didn't get any power numbers from the run. They said they have to set the start and end points in mph then run it for a pass. Didn't make much sense to me, but that was close to 4 years ago, don't remember the details.
Only ever ran on a dynojet after that, and you just hit a button and watch the screen.

That's all the info I was looking for. http://****************.com/smile/emthup.gif


----------



## Tom A (Oct 20, 2004)

*Re: (secondgen)*

I posted this in the original thread in the 8V forum, but in case anyone missed it, here it is again:

_Quote, originally posted by *Tom A* »_You guys might find this interesting, I know I did.
There is an active racing Series in South Africa called Formula GTi, that uses a spec VW "Parts-Bin" engine. They use a 1.8 block, dry sumped, 2L crank and rods, bore it out to 82.65MM using Audi pistons, 11:1 compression, with 40MM side draft carbs, a stock Hydro head and a 288º cam.
This combo gives an output of 150hp at 6700rpm.
Details here: http://www.formulagti.com/
The gentleman I corresponded with about the setup did not mention if that HP number was at the crank or the wheels, but they use a Hewland tranny, so the losses would be lower than a stock unit, I would think.
Either way, that is an impressive number, particularly with stock heads.


----------



## tdogg74 (Mar 1, 2002)

*FV-QR*

that sounds to be at the crank..which would equate to about 130whp. Thats about right for that bore/compression/cam duration.


----------



## Issam Abed (Feb 12, 2004)

*Re: (Tom A)*


_Quote, originally posted by *Tom A* »_









Tom where can I get more information about this engine? More specific the water pump set up? That is from SCAT enterprises from the early 80's and I have been looking to buy it for over 2 years now.
Any info would be greatly appreciated.


----------



## Tom A (Oct 20, 2004)

*Re: (Issam Abed)*

Some details from the car owner here:
http://corner-carvers.com/foru...nt=31
Looks to be something made locally to the series in South Africa:

_Quote »_The pump is a different kettle of fish. The pump combines both the functions of oil and water pump. The first section is a cast piece that copies the original VW water pump, it uses the impellor of the standard pump, and utilizes a gland seal to stop water getting into the oil pump module.
The oil pump section is 5 machined aluminum pieces. The actual impellors are the same as the standard VW oil pump, except that there are six of them. It is a three stage pump. Stage 1 receives oil at the bottom and pumps it into the engine from the top. The second and third stages scavenge oil form the sump and pump it back to the reservoir.
This set-up works extremely well. The only problem is that the combined oil/water pump is expensive, and the company will only turn them out in batches of 10. Should you have enough interest, I could enquire as to price to export them, but you are looking at a price well north of US$ 1 000.00 each. 

Here is a photo of the pump apart:








Tom


----------



## Issam Abed (Feb 12, 2004)

*Re: (Tom A)*

For $1000 USD I would do it...tell him to get in contact with me asap please
Thanks!


----------



## nick526 (Sep 29, 2006)

*Re: (Tom A)*

That's pretty cool http://****************.com/smile/emthup.gif I wonder what the service life of that unit is. With the oil and coolant in a common pump I'd imagine it would have to be torn down and inspected after every race.


----------



## shannonekermans (Oct 9, 2007)

i live in south africa and will be there in a month are you looking to import these things?


----------



## Tom A (Oct 20, 2004)

*Re: (Issam Abed)*

Just to clarify, he didn't say $1000, he said "well north of US$ 1 000.00 each", and you would still need the dry sump oil pan and all the additional plumbing and tank. That information is also from mid 2007, no idea if the price or exchange rates have changed since then.
I contacted the engine owner for more info, I will pass on what I get.


----------



## Issam Abed (Feb 12, 2004)

*Re: (Tom A)*


_Quote, originally posted by *Tom A* »_Just to clarify, he didn't say $1000, he said "well north of US$ 1 000.00 each", and you would still need the dry sump oil pan and all the additional plumbing and tank. That information is also from mid 2007, no idea if the price or exchange rates have changed since then.
I contacted the engine owner for more info, I will pass on what I get.


All I care about is a source for that cast housing.That was originally done by SCAT Enterprises when they had there Supervee program.When you call SCAT today they dont even remember producing parts like this.


----------



## chippievw (Dec 5, 2006)

*Re: (Issam Abed)*

stumbled on this on my high rev travels http://www.f1technical.net/for...=6129 http://****************.com/smile/emthup.gif


----------



## mudanddust (Oct 24, 2007)

*Re: Let's Talk about making Naturally Aspirated Horsepower (vwhammer1)*


_Quote, originally posted by *vwhammer1* »_I sincerely think that the cylinder head could be an issue if you are trying to build a high revving engine using the 8V head.
You will really have to open it up and run the biggest valves you can along with a monster cam.
I would hate for you to do all that reving only to be limited by the head flow.
I know we all want to prove that the 8v can make power but it would be a better use of the bottom end of this theoretical engine if a 16v head was used.
I know I am comparing apples to oranges here but I suppose if a Nascar engine can make 750-800 hp using a 2 valve per cylinder engine then maybe an 8v head might work on this engine if it is really reworked.
But look at the amount of modifications and cash that goes into the heads on a Nascar engine.

personally i am working on a 16v project, but i have a buddy who is all about 8v's. he took an engine building class at a local tec school and got to play around with a flow bench. He found that the larger diameter stock valve heads with a nice port can flow better than a big valve head. these were his findings, but i would assume that this has to do with the greater distance the intake charge has to flow over a larger valve vs. a smaller one?


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (mudanddust)*


_Quote, originally posted by *mudanddust* »_
...He found that the larger diameter stock valve heads with a nice port can flow better than a big valve head. these were his findings, but i would assume that this has to do with the greater distance the intake charge has to flow over a larger valve vs. a smaller one?

Could you find out a little more about this? I'm not quite sure I understand.
VW really only had two valve sizes in their 8v heads. There were the small valves which came on some 1.8L motors (and every smaller displacement). Then, there were the "big valve" heads which was the GTI head, Digifant heads, and the later crossflow.
I'm an 8v enthusiast, for many reasons... I think that a lot of tuners forgot about developing the 8v, once the 16v came out in the late 80's. Of course, companies such as Techtonics, Drake, Bertils, etc. have put quite a bit of development into the counterflow heads, but I wonder if there isn't more power to be made with the application of some modern techniques.


----------



## EL DRIFTO (Jul 11, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

this certainly isn't the first time someone figured out how to get an even larger valve into something and it hurt overall power area under the curve
in fact, it's seems cosmetic at best considering the larger oe valve does the trick
perhaps the effective curtain area is reduced, literaly, since the only curtain area obstrucion is next to the cylinder wall


----------



## Scorp67 (Apr 30, 2009)

Sorry to digress back to the previous page
*Att South Africans*
Regarding the formula GTi engines, are they prepared by a company or each team, if it is a company then who?
I am interested as who is a reputable name for working on VW engines, in particular the heads
As an aside I dont think iv ever seen these particular cars racing at kyalami??may be i have but never took particular note of them


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (EL DRIFTO)*


_Quote, originally posted by *EL DRIFTO* »_this certainly isn't the first time someone figured out how to get an even larger valve into something and it hurt overall power area under the curve
in fact, it's seems cosmetic at best considering the larger oe valve does the trick
perhaps the effective curtain area is reduced, literaly, since the only curtain area obstrucion is next to the cylinder wall

A very good point. http://****************.com/smile/emthup.gif 
Another thing to keep in mind is the ratio of intake & exhaust port flow. I can speak for myself and say that a lot of time is spent making the intake side flow well, but getting the proper ratio is forgotten about.

_Quote, originally posted by *Scorp67* »_
...I am interested as who is a reputable name for working on VW engines, in particular the heads


A few that come to mind are:
Bertils Racing Engines (BRE) - Retired
Techtonics Tuning
Eurospec
There is also TM Tuning over in Europe.
Some older companies would be Drake and Oettinger.
There are also several companies on here that have a lot of experience with the VW heads:
Southern California Cylinder Heads (SCCH)
Port Tuning (LR Engineering) 
And many others who put a lot of time and effort into the 8v.


_Modified by Jettaboy1884 at 9:22 AM 6-10-2009_


----------



## EL DRIFTO (Jul 11, 2004)

*Re: (Scorp67)*


_Quote, originally posted by *Scorp67* »_Sorry to digress back to the previous page
*Att South Africans*
Regarding the formula GTi engines, are they prepared by a company or each team, if it is a company then who?
I am interested as who is a reputable name for working on VW engines, in particular the heads
As an aside I dont think iv ever seen these particular cars racing at kyalami??may be i have but never took particular note of them

here are some specific current #s
http://scientificrabbit.com/node/3


----------



## Tom A (Oct 20, 2004)

*Re: (EL DRIFTO)*

Their rules require stock heads, so I don't know if any of them could help you. Unfortunately their forums are overrun with spam, so that is a waste of time.
There is an email address for the series webmaster, gerrit "at" formulagti.com
You could also show up at their next event and talk to everyone. Here is the schedule:
http://www.formulagti.com/race_schedule.htm


----------



## Scorp67 (Apr 30, 2009)

Thanks every one for replies, will look into it, its not like i need much persuading to go wondering around the pits at a race track


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Scorp67)*

Here's a good article about volumetric efficiency with engines:
http://www.epi-eng.com/piston_...y.htm


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

And Here's a good article about OHC versus Pushrod engines. It's a good read:
http://www.autoblog.com/2005/1...-rant


----------



## demelok (May 7, 2006)

*FV-QR*

so finally i put all my homework together and finished collecting all my parts. but i am very oped to advice 
i'm still rocking hyd lifters here so bare with me im not as extreme as all you haha
ohk heres the list
# 2.0 ABA xflow swap obd1
# head ported to gasket
# 3 angle valve job
# decked head
# TT HD dual valve springs
# mk4 intake manifold swap
# 276 TT cam
# mk4 2.0 injectors 
# shaved flywheel
# usrt smart linkage
# mk4 exhaust manifold swap
# 2.25" tt catback
blocks still at the machine shop ,its getting decked,dip'd and honned . 
also on the aba swap i never wired the VSS in so i never had tach and had a very fast rev limiter. i was told my car was taching out @ 5900 rpm if i didnt wire that in. and i believe it , it cuts out pretty quick.
so if i did wire it in i would be looking at full range tach for the aba @ 6300 then burnt chip would push that a little bit higher. 
and also i havnt ran o2's in this car ever! never had them wired up. and i doesnt really seem to be effecting it that much. 
i'm pretty happy with the results so far. considering all i did was slap the 270 in my head without and headwork. so im really looking foward to the results now. 
i havnt finished the swap yet. of all the goodies. but heres some numbers of last year 
# WITH OLD 270* AUTOTECH CAM
# 15.5 at 88 mph - import wars
# 15.4 at 85 mph - import wars
*cough* daily driver 
any advice? thanks 


_Modified by demelok at 9:42 AM 6-26-2009_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (demelok)*

Here's another good article, with some very nice work:
http://www.bonnevilleforum.com/t267503/


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (demelok)*


_Quote, originally posted by *demelok* »_so finally i put all my homework together and finished collecting all my parts. but i am very oped to advice 
...
*cough* daily driver 
any advice? thanks 


While you'll probably get a few good responses in here, I'd suggest you post it up in the sibling thread to this one.
Located here: http://forums.vwvortex.com/zer...age=5
It's currently archived, but I'd like to see you bring it back up. http://****************.com/smile/emthup.gif


----------



## demelok (May 7, 2006)

*FV-QR*


_Quote, originally posted by *Jettaboy1884* »_
While you'll probably get a few good responses in here, I'd suggest you post it up in the sibling thread to this one.
Located here: http://forums.vwvortex.com/zer...age=5
It's currently archived, but I'd like to see you bring it back up. http://****************.com/smile/emthup.gif 


bumped the 8v thread


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (demelok)*


_Quote, originally posted by *demelok* »_
bumped the 8v thread 

Thanks!
Here's another article. It's a bit short, but has a decent explanation and formulas for calculating intake runner length.
http://mgcgti.com/Page40.html


----------



## secondgen (Jan 9, 2004)

*Re: FV-QR (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
Thanks!
Here's another article. It's a bit short, but has a decent explanation and formulas for calculating intake runner length.
http://mgcgti.com/Page40.html

Can the same equations and theory be applied when deciding how long a ITB manifold should/can be? If so, would it be pre-butterfly intake length or could it be overall intake runner length (assuming that the throttle is @ WOT)?
for example:








compared to:


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (secondgen)*

That's a question which I have wondered myself, and did a little reading into the subject. Here's what I got from it:
One of several reasons to use an ITB setup is so that you can run a cam with large duration. By not having a plenum at the end of the runners, the valve events of one cylinder will not be able to have an effect on the others. ITB's are also considered less restrictive to flow than the typical intake manifold. But there's a catch:
With ITB's, you can still use different length runners and velocity stacks (trumpets/bellmouths) to tune the resonant pulse waves. This will allow for the individual port resonant tuning.
However, if the ITB's are drawing atmospheric air immediately from the end of the runner, then you loose the ability to utilize helmholtz tuning of the plenum. (See the Grapeaperacing article for explanation) Many people are willing to sacrifice this, so that they can run a lopy cam and still manage to idle. However, it seems to me that the really high horsepower motors use an intake with a plenum, so that they can extract that extra power from the helmholtz tuning.
At WOT, the placement of the butterflies shouldn't have an effect on the resonant and helmholtz tuning. (The placement will have an effect on throttle response though).
So, to answer your question: The first set of ITB's pictured would allow for helmholtz tuning of the whole intake tract by using a longer or shorter intake pipe (Honda guys call it a Short Ram intake).
The second set of ITB's could only use resonance tuning of the individual runners, because there is no plenum or intake tube to tune.
I hope that makes sense...











_Modified by Jettaboy1884 at 10:19 AM 7-7-2009_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Here are a few more links. (I need to spend time at some point, and bring all these links to the first page)...
This link has articles featured in "Race Engine" magazine, which I find to be an excellent resource of information. You can view each article as a PDF. or download each one. They're very interesting, but often very far over my head!
http://www.profblairandassocia....html

And here are a couple of very old documents from the National Advisory Committe for Aeronautics. They give some interesting insight into the discovery of pulse tuning and volumetric efficiency.
"Effect of an Intake Pipe on Volumetric Efficiency of an Internal Combustion Engine" 
http://ntrs.nasa.gov/archive/n...1.pdf
"Dynamics of the Inlet System of a Four-Stroke Engine"
http://ntrs.nasa.gov/archive/n...8.pdf


----------



## IamBigTuna (Sep 10, 2008)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

A properly tuned plenum can capture and harness pulses and velocities and create positive air pressures. Open air ITB's are fading fast racing due to the newer plenum technology and data. Most ITB users never attempt to tune the lengths, if you do put in the effort then the gains on the properly tuned plenum would win.


----------



## EL DRIFTO (Jul 11, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (IamBigTuna)*

i've heard of porsche 356 engines
testing over 100% VE
i'm sure they're others, just the first story i heard
which could only be explained by boost
in other words, when the intake valve closed
(everything else perfect obviously)
the momentum of the mass of air developed
on the intake stroke, coming down the in runner
actually shoves air into the chamber
as the intake valve closes
higher than atmos press in cyl
so much "boost" 
it overcomes oil pump, cooling etc to get 100%+ VE NA
for ex:
1.6 liter @ 7000 rpm
can only "pump" a certain volume of air = 100% VE
more power at the crank than that means...
i think it was 170 chp
race gas
_Modified by EL DRIFTO at 4:03 PM 7-8-2009_


_Modified by EL DRIFTO at 3:07 AM 7-9-2009_


----------



## mudanddust (Oct 24, 2007)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
Could you find out a little more about this? I'm not quite sure I understand.
VW really only had two valve sizes in their 8v heads. There were the small valves which came on some 1.8L motors (and every smaller displacement). Then, there were the "big valve" heads which was the GTI head, Digifant heads, and the later crossflow.
I'm an 8v enthusiast, for many reasons... I think that a lot of tuners forgot about developing the 8v, once the 16v came out in the late 80's. Of course, companies such as Techtonics, Drake, Bertils, etc. have put quite a bit of development into the counterflow heads, but I wonder if there isn't more power to be made with the application of some modern techniques.

He was saying that with porting you can get the larger stock valve size to flow as well as a big valve head. Thats what he came up with from his own resarch


----------



## Lord_Verminaard (Apr 6, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (mudanddust)*

Excellent thread. Just read the whole thing. http://****************.com/smile/emthup.gif
Brendan


----------



## HPR (Oct 31, 2004)

*Re: (g60_c)*

this F3 engine is based on a N.A FSI engine AXW
its homologated by the F.I.A as a CBF engine
The engine is developed and build by http://www.spiess-tuning.de for VW
They do the engines for vw and opel motorsport

16 valve, non vario cam timing 
bore 83mm / stroke 92.3
Dry sump
102 octan fuel
Bosch MS3.1 ecu
Port injected 
Water temp typical 65 / 70 C ( above that, there is power loss )
Weight ca 95/ 98 kg 
The engine has to pull all air trough a 26 mm restrictor, behind the restictor ( wich is only 3mm long) there is a tube that tapers out to get laminar flow and get as much air in as possible, that why there is such a big airbox.
Power output is about 212 hp @ 5800rpm /ca250nm @5400rpm 
( thats what they will tell.)
I believe the best engines give close to 220 hp
Compression ratios are typical very high 15/1 to 17/1 ( official 13/1 )
These engines are always on the edge off destructive detonation and every revolution adjusted by the electronics 
These engines are full off tweaks, smaller bearings, low friction coatings, all parts are weight optimised , Short duration/ high lift/high acceleration cams cnc ported head and inletmanifold
Slipper piston with 2 rings, etc..


----------



## The Green (Oct 5, 2002)

*Re: (HPR)*

Too bad there is not much to be seen on their site..
I see you are from Antwerp?
Googled your nickname, but did not popup a compagny


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: (The Green)*

Bump. http://****************.com/smile/emthup.gif


----------



## Road Boss (Jul 16, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

This links on the first post needs to be updated.


----------



## VWn00b (Mar 4, 2005)

*FV-QR*

When talking about individual throttle bodies, how big is _too_ big?
I know TWM makes 45, 48, and 50mm bodies, and Jenvey has an almost orgasmic list of single and twin throttle setups.
When talking about flow and the ability to actually make the power desired, when does the size of the body actually begin to affect where in the RPM range power is make? How big are you able to go without going overboard?
I noticed Jenvey has 60mm TOCA bodies made for the BTCC series, and I started drooling.


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (VWn00b)*

45 mm is good for 250 hp and even more ( so for most of us )
on 48 mm you can find some more top end, mainly above 7000 rpm
and sometimes have gains in the lower rev range too.
50mm is for 9000rpm or 150hp/liter applications
i would not use 48mm TBs on a 200 hp engine as you need gas 
velocity, Remember fast HP and slow HP (trottle respons)
races are won by TQ, not ultimate HP, the ability to climb te revs.
a kitcar engine ca 290 hp use 47mm TBs
60mm TOCA TB is used as single TB 
but even then they make +280 hp


_Modified by HPR at 7:29 AM 9-4-2009_


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_When talking about individual throttle bodies, how big is _too_ big?

A question I have always wondered as well. http://****************.com/smile/emthup.gif 
Thanks for the reply HPR.


----------



## Issam Abed (Feb 12, 2004)

*Re: FV-QR (HPR)*


_Quote, originally posted by *HPR* »_
50mm is for 9000rpm or 150hp/liter applications

So pretty much no road going Volkswagen engine needs 50mm ITB's


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (Issam Abed)*

No, 50 mm is far too big 
1600 engines 16v or 20v 200-220 [email protected] 9000rpm use 42 mm ITB`s
in european rallycross
even the V8 3.6 dtm used a 42.5mm slide injection


----------



## ny_fam (Apr 3, 2004)

*Re: FV-QR (HPR)*

190 HP 1.6 8 valve formula super vee engines use 32mm.
Velocity is your friend...


----------



## Issam Abed (Feb 12, 2004)

*Re: FV-QR (ny_fam)*


_Quote, originally posted by *ny_fam* »_190 HP 1.6 8 valve formula super vee engines use 32mm.
Velocity is your friend...


Its also an 8V...not much air it can injest considering the size of the intake ports.


----------



## fourthchirpin (Nov 19, 2004)

*Re: FV-QR (ny_fam)*


_Quote, originally posted by *dtrfab;746187* »_Just wanted to share my experience with some parts i've been playing with this pass year to show what kind of gains i've gotten out of the parts I've invested my money into...Last year was a rough season for me... I went out to 3 races and in all 3 races my car had nothing but problems. mostly electrical. I spent most of the winter resolving that issue and come to find out that the engine harness i made lacked some shielding around some vital signal wires causing the computer to shut off.. Last year my motor made 295HP basic k24 with full dome pistons mild ported head with stage 3 skunk cams on 52mm TWM's. I always new that the motor had another 30-40Hp without even touching the inside. First thing i replaced was my dinky throttle bodies and got some real ones..I contact Scott of Kinsler Fuel injection and got setup with set 62mm with 2mm oversize window port at 10degree taper...here is the difference from the just changing out the throttle bodies








To be fare i picked out the average HP dyno's on high side..on some pass i picked up much as 12HP average i would say was around 9HP from 8-9 grand.. exactly where i expected to pick up..
So with the switch over to the 62mm gaining more top end i experimented with a new header design one that doesn't change to much in pipesize and collector size but more focused on the length as now i have a motor that operates as high as 9500RPM This new header design is an overall 2 1/2" shorter then the previous header i ran...The only bad thing is didn't get a chance to compare apple for apple on old and new header because i cut the old one up to make the new one... 








old header








Along with this new header i installed a 3 stage dry sump oiling system 








When i got the car back on the dyno i was in for a surprise 








Night and day difference in what i made over without the sump.. I was told prior to install of the sump system to expect about 15hp gain but from the graph it shows i picked up 18-22hp and the power band had shifted due to the fact i had altered the layout and length of the header...
Back to Scott at Kinsler he wanted to to try out his upper rail kit for my 62mm and i was told to expect about 4-6 Hp from changing the positioning of the injector and boy was he on the dot...The upper rail kit was a breeze to install and Scott also sent me a set of dummy injectors to plug my primaries that i wasn't going to use anymore...

















here is the difference between the switch from bottom to top.. With the initial install it took us a few runs to fine tune the fuel mixture as it ran very rich without pressure change. I would guess that it is mixing more effciently and causing the rich mixture..








Here is an over all graph of all the different things i've tried to make more power and to see the difference in graph change..








So with some decent power i got chance to run the car this pass weekend... 
http://www.youtube.com/watch?v=NIrFbXaT98s

i trashed second gear again so my 1-2 transition is not as fast i would like but i still got it to go down...with a new ppg 4 speed box coming in 2 weeks.. i hope that i will be excepted into the all motor 9 second club... till then..
NOTE:car is weight in at 1600lb my BOTI weight for my car running a smaller 2.4L oppose to a 2.6L


and i thought 50mm was forbidden. lol


----------



## Jettaboy1884 (Jan 20, 2004)

*Re: FV-QR (fourthchirpin)*

Is it just me, or does it seem that naturally aspirated Honda setups are lightyears ahead of what VW performance enthusiasts do? Why is that? (And I'm not talking about the 8v motor, as most have given up on it a long time ago).


----------



## fourthchirpin (Nov 19, 2004)

*Re: FV-QR (Jettaboy1884)*

Products come out for their motors alot faster, because there is demand. plain and simple.


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (Jettaboy1884)*

It's not just you.
Honda just has a better head design than we do. They make more power because they flow soo much better.
For a K20 motor to make 200whp, it only needs 4 mods: cams, header, exhaust, and K-Pro.
You can't do that with an ABF or similar 16v motor without opening up the motor.

_Quote, originally posted by *fourthchirpin* »_Products come out for their motors alot faster, because there is demand. plain and simple.

The Honda aftermarket is very big, but even if the same R&D that is put into making power out of Honda's is put into a VW 16v, we'd still wouldn't match them in #'s.


_Modified by VWn00b at 9:54 PM 9-24-2009_


----------



## fourthchirpin (Nov 19, 2004)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_It's not just you.
Honda just has a better head design than we do. They make more power because they flow soo much better.
For a K20 motor to make 200whp, it only needs 4 mods: cams, header, exhaust, and K-Pro.
You can't do that with an ABF or similar 16v motor without opening up the motor.
The Honda aftermarket is very big, but even if the same R&D that is put into making power out of Honda's is put into a VW 16v, we'd still wouldn't match them in #'s.


your comparing a 2003 motor to a 16v abf that is based off of much older technology. I can't deny honda heads flow ohh too well for us but still the things they do over there make us look like dinosaurs, we need more people thinking out the box with NA.


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (fourthchirpin)*


_Quote, originally posted by *fourthchirpin* »_...we need more people thinking out the box with NA.

Well, if you want to talk new technology, you could build a NA FSI motor.
Motec or Bosch Motorsport ECU would control the injectors; that's if you wanted to keep the FSI part of the motor.
Otherwise:
-ITBs
-Cams
-High compression headgasket
-Valvetrain
-Plug the FSI ports
Wouldn't even need to touch the bottom end.


----------



## HPR (Oct 31, 2004)

Our 16V ( KR, PL / 1800cc) is an 1984 engine and updated to 2.0 l in 1993
basis architecture is 25 years old
VW engines have small bore / Long stroke and relative small valves ,
we have to live with that

I keep saying 50mm is way to big , and 50 mm is for 9000RPM or 150hp/ liter
What the Honda here confirms 
But if he put it on a 200/ 220hp Honda the story is likely different
Using 50mm on a really strong VW 16V will gain also 8 hp or so,
but on a lower spec engine you lose so much midrange ...even on top
The further you place the butterfly away from the inlet valves the bigger you can go
To go big, you need very good flow / a very strong engine to make it work
most here have everyday street cars, then you need good midrange to keep it driveable
most here are talking in the 190- 240 hp range ( 16V ), 
paying the bills with their own money, 
experimenting with expensive inlet systems, etc is out of the box for most
take good , proven parts that work and develop from there in small steps
most extreme parts are not for us , but they do their job well on high spec engines
HP numbers sound good ,but in the end its the Chrono that tell you how fast you really are
And believe me its not always those with the ultimate HP 




_Modified by HPR at 2:23 AM 9-25-2009_


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (VWn00b)*

I am working on a N.A FSI engine
First target : 280hp @ 8000
Specs will be: 
AXW basis engine
CNC ported head
+ 1mm Ferrea valves 34.8 / 29 mm
Valvetrain parts , no vario cam
Custom made cams
STD headgasket 1.0mm
HPR inlet manifold
4 single TB + 380cc injectors
4 dummy FSI injectors
82.5 bore / 92.8 stroke
Custom pistons 13/1
Steel rods 
Remove balance shafts
Wet sump
std AXW head tested on Superflow 1020 (bore 84 mm) @10``H2O 
leak is 0.7 inlet and 0.8 exhaust
inletvalve 34mm troat 30mm seat 1.3 mm
exhaustvalve 28 mm troat 23.5mm seat 1.8 mm
inlet	
2 mm 36.0 cfm 
3 mm 54.1 
4 mm 71.1 
5 mm 86.0 
6mm 100.2 
7mm 113.3 
8 mm 125.2 
9mm 134.1 
10mm 138.4 
11mm 140.7 
12mm 143.3 
13mm 144.7 
14 mm 145.6 
15 mm 146.5 
no valve 143. 
Exhaust
2mm 33.6 cfm
3mm 51.3
4mm 66.7
5mm 78.2
6mm 85.5
7mm 89.6
8mm 91.9
9mm 93.5
10mm 94.7
11mm 95.6
12mm 96.5
13mm 97.2
14mm 97.6
15mm 98.1
no valve 104

Expectations are that after porting flow will be close to 150 cfm @ 11 mmm on inlet with std valves and exhaust about 115 to 120 cfm @ 11 mm 
( numbers @10``multiplied x 1.67 )
flow @ 28``H20 should be:
inlet /exhaust
2mm 60.12 / 56.11
3mm 90.34 / 85.67
4mm 118.73 /111.39
5mm 143.62 / 130.59
6mm 167.33 / 142.78
7mm 189.21 / 149.63
8mm 209.08 / 153.47
9mm 223.94 / 156.14
10mm 231.13 / 158.15
11mm 234.97 / 159.65
12mm 239.31 / 161.15
13mm 241.65 / 162.32
no valve 239.8 / 174.0



_Modified by HPR at 3:49 AM 9-25-2009_


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (fourthchirpin)*

327.74 hp / 2354cc x 1984 cc = 276.22 hp if a VW 2.0litre engine
With 588,5 cc/cylinder you can use bigger TBs
Comparing apples and Bananas
The cars in WTCC and IRC make 280-300 Hp from a 2 litre on a single 64 mm TB !!!
And 220hp F3 Engines pull all air trough a 26 mm Air Restrictor,
A Chevrolet LS7 AMLS engine makes 590hp on 2 x 31.2 mm Air Restrictors


----------



## Lord_Verminaard (Apr 6, 2004)

*Re: FV-QR (HPR)*

230+ cfm, now we are talkin. That outflows the 20v correct?
The old 16v is pretty much a wasted go. It was a bad head design right off the bat. In terms of design, the 8v is better. Not that it makes more horsepower but there are a lot less design flaws to work with. 16 valves almost always outflow an 8v of the same displacement. The only 8v I wish VW used was the Fiat-design hemi 8v, those things flow major air for only having 8 valves.
Brendan


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (Lord_Verminaard)*

a ported 16v on std valves flows @ 10.2 mm - 142cfm @10``H20
or 237 @28``h20 , but its allows more lift

20V AEB big port head flow @25``
portLift Inlet Flow Exhaust Flow 
0.05 42.8 31.4
0.1 86.7 70.6
0.15 124.3 100.6
0.2 151.8 120.6
0.25 177.8 140.8
0.3 198.9 154.7
0.35 213.4 170.9
0.4 225.2 180.3
0.45 233.1 188.7
0.5 237.6 195.4
courtesy of BOBQZZI 1.8T/716hp




_Modified by HPR at 12:13 PM 9-25-2009_


----------



## VWn00b (Mar 4, 2005)

*FV-QR*

Hmm...an FSI NA build sounds very tempting right now.


----------



## fourthchirpin (Nov 19, 2004)

*Re: FV-QR (VWn00b)*

exactly what I was thinking as i typed that. but like I said alot of people dont like to be the one to test stuff out and fail.


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (fourthchirpin)*


_Quote, originally posted by *fourthchirpin* »_exactly what I was thinking as i typed that. but like I said alot of people dont like to be the one to test stuff out and fail.

Well...I wouldn't think it would be that much more trouble to test out.
From a cost perspective, I think you could get way with an NA FSI build for less than a 16v or 20v NA build, and probably make very similar power.
-Stock Long block FSI motor
-High compression headgasket (CR up to ~11:1)
-Custom intake manifold and header
-SEM of choice
That's really all you need right there to get the build going. Don't touch the cams or pistons, and block off the FSI injector ports.
This would give you a good foundation to work with, and allows you to do minor testing on a motor that's already broken in.
Afterwards, you can look at head porting, bigger cams (I'm sure CAT, Schrick or Piper already has NA cams. If not something that could easily be adapted)


----------



## PowerDubs (Jul 22, 2001)

*Re: FV-QR (fourthchirpin)*


_Quote, originally posted by *fourthchirpin* »_exactly what I was thinking as i typed that. but like I said alot of people dont like to be the one to test stuff out and fail.

I test stuff out and fail all the time.. I don't mind it much as building and testing is half the fun of the hobby to me.. but I have certainly wasted a _lot_ of money in the process.


----------



## Fast929 (Nov 13, 2004)

*Re: FV-QR (PowerDubs)*

I'd agree with most of what HPR is saying here. Need to balance out the entire package. Too many try to over-cam motors without enough dymanic compression (cr means nothing, actual cylinder pressure is what dictates setup requirements).
I'm trying to run 12.5:1 on pump by balancing static/dynamic based on pretty serious overlap. We'll see how it all works out.
My 16v is coming together right now (finally). It'll be interesting to see how it works out.
My head flows in excess of 240+cfm intake and 180+cfm exhaust.
Spec as follows:
PL based 16v 1915cc (Bore x stroke 84mm x 86.4mm).
Custom 12.5:1cr Wiseco's
Pauter rods
K-Edged, lightened crank
Big Valve Head (Supertech valve train, Ti retainers, solid lifters)
VWMS 300's (.522" lift)
48mm Black Top ITBs (Jim @ Racecraft)
Head has been worked several times and at this point, is pretty serious... Gotta shout out to Jarod from SCCH. Guy can work some magic!!! http://****************.com/smile/emthup.gif 



_Modified by Fast929 at 7:28 PM 9-25-2009_


----------



## Fast929 (Nov 13, 2004)

*Re: FV-QR (Fast929)*

While I really like the Honda setup above, I'd prefer to see longer runner lengths tuned for primary pulse. Might pick up a bunch within the midrange (especially with the header/exhaust design). Very 2-stroke tuning basically.


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (Fast929)*


_Quote, originally posted by *Fast929* »_
Custom 12.5:1cr Wiseco's
VWMS 300's (.522" lift)
48mm Black Top ITBs (Jim @ Racecraft)


I'm basically doing the same build but thinking of a few different things.
-ABA block
-84mm Wossner pistons 12.4:1 (still undecided about these since I'm wanting 93 as well)
-Either Cat 283/279 or Piper 294's. If I do the Wossner's I think the Pipers might be a better choice.
-The AE111 throttle bodies I was thinking about porting out to 50mm straight through like what TOCA does with there setups. I haven't had a chance to take them apart yet. The screws on the throttle plates are stubborn.








I don't know what my head flows. Russ Jr. did a mild port on it, but it definitely looks nice.
BTW, where did you get the VWMS cams? I wouldn't mind have a few other parts from the mk3 kit car.


----------



## Fast929 (Nov 13, 2004)

*Re: FV-QR (VWn00b)*

I don't want to mess with the 4A-GE's because they are nicely taper bored so along with my custom intake mani with long'ish primaries, they should provide solid tuning and nice torque for small'ish motor. I want/need some area under the curve so I'll sacrifice the 3-5hp right at peak for the 10-15 under the curve.
Either way, I'm still shooting for way over 200whp with this setup....








VWMS stuff's from a friend


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (Fast929)*

I'll be happy with 200whp. Any more than that will just add to my ego.


----------



## Fast929 (Nov 13, 2004)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_I'll be happy with 200whp. Any more than that will just add to my ego.









I hear you. lol

I've got a lot of time and money invested. It may only last for minutes but it should make some power!


----------



## billyVR6 (May 8, 2000)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_Hmm...an FSI NA build sounds very tempting right now.

Every now and the I poke a stick at the one I have going on here.


----------



## billyVR6 (May 8, 2000)

*Re: FV-QR (HPR)*


_Quote, originally posted by *HPR* »_STD headgasket 1.0mm

I just ordered a new head gasket and went with thinner than stock for now.
Thanks for double checking your head gaskets against what I had measured here.


_Quote, originally posted by *HPR* »_4 dummy FSI injectors

I thought this at first, but decided to pull the head and eventually have the chamber welded.


----------



## VWn00b (Mar 4, 2005)

*FV-QR*

BTW, Fast, what engine management are you going to be running?


----------



## Fast929 (Nov 13, 2004)

*Re: FV-QR (VWn00b)*

MS tuned through Paul.
The guy is magic with MS stuff plus he already tuned Mendra's car and my setup, while different, is very similar (tuned Mendra's 20v to the tune of 198whp on hydro's).
Impressive http://****************.com/smile/emthup.gif


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (Fast929)*


_Quote, originally posted by *Fast929* »_MS tuned through Paul.
The guy is magic with MS stuff plus he already tuned Mendra's car and my setup, while different, is very similar (tuned Mendra's 20v to the tune of 198whp on hydro's).
Impressive http://****************.com/smile/emthup.gif 

When you get it tuned let me know. I'd like to take a look at your Timing and Fueling tables. My build is going to be very similiar to yours and I'd like to get a good starting point. That's also if Paul doesn't mind either.


----------



## billyVR6 (May 8, 2000)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_
Well...I wouldn't think it would be that much more trouble to test out.
From a cost perspective, I think you could get way with an NA FSI build for less than a 16v or 20v NA build, and probably make very similar power.
-Stock Long block FSI motor
-High compression headgasket (CR up to ~11:1)
-Custom intake manifold and header
-SEM of choice
That's really all you need right there to get the build going. Don't touch the cams or pistons, and block off the FSI injector ports.
This would give you a good foundation to work with, and allows you to do minor testing on a motor that's already broken in.
Afterwards, you can look at head porting, bigger cams (I'm sure CAT, Schrick or Piper already has NA cams. If not something that could easily be adapted)

I missed this post, and it is exactly what I am doing with it. I had got distracted with Honda parts for a while that set things back, but it coming along now. Slow, but there is progress. The compression is high/er to start with, but still need to see how close to the claimed 11.5:1 it really is. I have a dyno from somewhere that puts it at 138-140whp in bone stock form. There are a lot of little things that may help wake that engine up once they are removed.


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (billyVR6)*

11.5/1 C.R is already STD 
( by using a headgasket 0.8mm gives 11.78 /1 )
by using ITBs 45mm and using still FSI 
long headers and an up rated cat back system
must be about 200 fw hp
With cams around 220 HP ?
( i made an inlet manifold that can be used FSI and/or EFI
weber DCOE style or 4 single TB )
only Schrick has some mild cams , as far as i know

the piston is not the shape we want 
(very high dome with a bowl in the middle)
i will replace them against classic pentroof type pistons


----------



## billyVR6 (May 8, 2000)

*Re: FV-QR (HPR)*

11.5:1 is the factory spec details, I just haven't confirmed this myself to see if this really holds true.
I did end up putting an order in for a thinner gasket, but went a little thinner than 8mm though.
Schrick still offers the one N/A cam set, short duration with high lift. Cat has been stringing us along for over a year, last month Ludo mentioned a September release but I am yet to see anything come through my inbox with specs and pricing. I have seen no other companies offer this platform, but haven't looked in a month. Either way, cams will not in my budget for a long time.
I do have a set of 45's here but hesitate to them to use. I am just not big fan of individual throttles, especially fwhen it comes to power levels under the 200whp target. Now that I do not have to adhere to race regulations anymore I picked up a set, mainly just to have them, adn still was very selective about cost/size/brand. I still really prefer and plan to run a single TB manifold.
The header is a long tube 4-2-1 set up.

_Quote, originally posted by *HPR* »_the piston is not the shape we want 
(very high dome with a bowl in the middle)
i will replace them against classic pentroof type pistons

I have to run these pistons for now, and they are the only thing that I can see being detrimental at this point. How much, I have no idea, but I guess that I will find that out soon.



_Modified by billyVR6 at 2:12 PM 9-29-2009_


----------



## need_a_VR6 (May 19, 1999)

*Re: FV-QR (VWn00b)*


_Quote, originally posted by *VWn00b* »_That's also if Paul doesn't mind either.










Not at all. However, tunes for cars that run speed density are very setup specific so even if the setup is 'close' the tune will probably still need to be changed quite a bit. Heck even just changing from a 67mm to a 75mm tb changed the tune completely.


----------



## HPR (Oct 31, 2004)

*Re: FV-QR (billyVR6)*

attention with using a thin headgasket,
at TDC the pistons are at the same level as the bloc 
by still using stock Rods ( they stretch )
06-08 mm is about as low as possible 
going any lower will be squish 0,0 mm at high revs
its a dangerous game !


----------



## billyVR6 (May 8, 2000)

*Re: FV-QR (HPR)*

Yes, thanks for the heads up. The one I ordered is thinner than .8mm, but not by much: .030" (.762mm). I did have a .027" (.685mm) gasket scheduled, and ended up calling back the next day just to play it safe. After thinking it though a bit more I really didn't feel it would be worth having any possible issues come about.


_Modified by billyVR6 at 12:06 PM 9-29-2009_


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_
Not at all. However, tunes for cars that run speed density are very setup specific so even if the setup is 'close' the tune will probably still need to be changed quite a bit. Heck even just changing from a 67mm to a 75mm tb changed the tune completely.

I'll be running a Haltech E6X with TPS for load, so obviously I can't use your MS files, but screenshots would work.
I only asked about sharing tunes because I'd like to see how a similar motor is setup so I can atleast get the thing running decent enough to drive it to the dyno.


----------



## need_a_VR6 (May 19, 1999)

*Re: FV-QR (VWn00b)*

Alpha-N cars are even worse! I'd just get the thing running, lock the timing or keep it conservative and rough the fuel in to drive. The way MS calcs load from the VE table is different. You can see how it should 'look' but the numbers would be different.


----------



## VWn00b (Mar 4, 2005)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_Alpha-N cars are even worse! I'd just get the thing running, lock the timing or keep it conservative and rough the fuel in to drive. The way MS calcs load from the VE table is different. You can see how it should 'look' but the numbers would be different. 

Do you think tuning off the MAP would be easier? With the Piper cams I plan on running I don't think it's going to be and better though.


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## need_a_VR6 (May 19, 1999)

*Re: FV-QR (VWn00b)*

On throttles, nope.


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## Fast929 (Nov 13, 2004)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_On throttles, nope. 

I agree. Too much air flow change in relation to throttle position. Rate of change is too great. You just don't have enough resolution with the MAP sensor....
It's getting close Paul


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## need_a_VR6 (May 19, 1999)

*Re: FV-QR (Fast929)*

My big single idles at 67kpa.. that's barely enough.


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (need_a_VR6)*

so i had a few hours friday & learned this intake manifold tuning math thing
http://mgcgti.com/Page40.html
http://forums.vwvortex.com/zerothread?id=4591568
how exciting to actually get it right BUT
now it doesn't idle
i was thinking idle "back pulses" to CIS
but with the TB closed @ idle,
maybe it's NO vacuum
once it drops below a certain point, it wont suck the plate @ all
literally i could wire the 5th injector to the idle switch
if i could get the idle to come back down below 4k








i've never thought of a vacuum gauge on a na car
i really like CIS, like an aircooled cis 930
but i've never had this 
ANY IDEAS ??








EDIT: well as the linked thread states, hooking up the idle switch & ISV got the ecus to do their intended purpose
to get a torqueless pos to idle with the AC on


_Modified by EL DRIFTO at 9:04 PM 10-5-2009_


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## ny_fam (Apr 3, 2004)

*Re: FV-QR (EL DRIFTO)*

Send me some data and I'll produce some lengths for your intakes. There are a few different schools of thought on the induction tuning. I use a set of imperically developed equations to calculate the proper lengths for tuning.
First order of tuning is getting the flow maximized and the velocities correct range for where you want the power. Then the wave tuning comes in last. 
What temperature is your intake air at?
What length are your runners . From plenum to intake valve seat.
What rpms do you want the tuning to be at? http://****************.com/smile/emthup.gif


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (ny_fam)*

the 16v scir intake mani
the 16v golf 1.8 mani & 
the 16v golf 2.0 mani all have different runner lengths & plenum sizes
i cut up two golfs & hose clamps
5.5", 6.0" & 6.5" runners with three different plenums
that make them all fit in the same brackets
EDIT: 5.5 - 6.5" are the measurements from the 5 bolt holes
to the plenum ONLY on the upper intake manifold sections
i shouldn't post sometimes
i just wanted to understand the universal equation
which assumes intake temp making speed of sound 1300 '/sec
& understand how much linear runner length i needed to cut out to get 500 rpm increase in torque peak rpm
i wish i had someone check my math, but i concluded 3.4" less length
would get me 500 rpm with 42mm dia & 18" port length
without any actual measurements, i got the oe torque peak @ 4750



_Modified by EL DRIFTO at 2:03 PM 10-6-2009_


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## ny_fam (Apr 3, 2004)

*Re: FV-QR (EL DRIFTO)*

Looks like your on the right track. Intake air temp has a big factor on the speed of sound.
You may need to get some rough exhaust measurements too. as the exhaust was similar tuning, and it may just happen that the point your trying to get more power is a trough(non optimal) for the exhaust.
You could also try lengthening the zip tube a 1" or 2". That has a similar effect
He is a run from my equations:
18" runners will get you a boost at the following rpms
6792
5036
3930
3167
2518
With intake air temp of 30 c
1" change in length moves the power about 300 rpms.


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## PowerDubs (Jul 22, 2001)

*Re: FV-QR (ny_fam)*

Sorry for the repost but this is somewhat related for sake of discussion.
On my old 16v I put a 42mm plenum onto 50mm runners and shortened the runners 1.5 inches. This was a direct swap for the standard 50mm upper. It increased the useful rev range favorably.
This was on a stock 2.0 block & head with just a euro intake cam, airbox, chip, catback.


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (ny_fam)*

thanks for the help
i just used the second part of the equation
helmholtz of cylinder & intake port valve open
which calculates only one resonance freq ?
i didn't bother with the 4 reflection one...
1" is the total variation of oe runner lengths...
i went ahead & put the oe back on last night to get the hood closed for the rain
& i noticed it pulls to 7 now, since i added even more fuel up top
i'm a retard & so much for the butt wideband
as far as the ex, i've read that generally speaking, it's way less influential
which pretty much gives you two options
i have the shortest tube with cat, which revs great, although tt told me it had 10 hp less than the proven long tube when i paid more for it on the phone
well, it's all good to know, especially since 1" is way more doable than 3
perhaps i'll shorten the oe scir mani 1"
since it'll still fit under the hood that way http://****************.com/smile/emthup.gif 
although last night's trip to dinner, i glanced @ the tach everytime i shifted & it said 6900, so it was just lean
^^^that custom 50mm is sex, that was the first one i ever noticed some time ago
now if i could get the same effect with two golf mani
it doesn't feel like i get any equations yet










_Modified by EL DRIFTO at 2:26 PM 10-6-2009_


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## redGTInj (Jul 6, 2003)

*Re: FV-QR (EL DRIFTO)*

that intake manifold, is on its way to MY house


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## PowerDubs (Jul 22, 2001)

*Re: FV-QR (redGTInj)*

Are you serious? PM me!! http://****************.com/smile/emthup.gif


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## shannonekermans (Oct 9, 2007)

ny fam. you say u use wave tuning last? if i may ask how do you design your runners then. ive read the helmotz thing and i understand the pulses are what creates the positive pressure. but does it matter what diameter the intake port is on the head. for example on an 8v the port is only 30mm in diameter. if the runners are 42mm will the change in diameter affect helmotz theory?


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## RipCity Euros (Sep 23, 2007)

*Re: (shannonekermans)*

Smaller diameter runners will result in faster gas speeds, thats why you dont just hog-out intake ports.


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## shannonekermans (Oct 9, 2007)

i understand that. i had a inside look on a 16v race head here where they actually sleeved the intake ports to make them smaller and changend the port shape completely. my interest is in a 8v motor that im building myself. from doing calculations it seems like if i run 30mm (ie the same diameter as the intake port itself) the need to make the runners 19 inches long. but will it also work if i use 40mm diameter runners with a lenght of say 13 inches just as an example?


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## Jettaboy1884 (Jan 20, 2004)

*Re: (shannonekermans)*


_Quote, originally posted by *shannonekermans* »_i understand that. i had a inside look on a 16v race head here where they actually sleeved the intake ports to make them smaller and changed the port shape completely. 

Interesting. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

Just a little New Years Bump.
I found this Excellent article about airflow into a bellmouth. Very interesting stuff. http://****************.com/smile/emthup.gif 
http://www.profblairandassocia...t.pdf


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## Jettaboy1884 (Jan 20, 2004)

*Re: (Jettaboy1884)*

Here's another good one:
http://autospeed.com/cms/article.html?&A=0442


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## notso2slo (May 1, 2006)

*Re: (Jettaboy1884)*


_Quote, originally posted by *article* »_In design terms, one can usefully conclude that “short and fat” is best with an optimum length criterion L of one diameter De, and an optimum entry diameter Di of some 2.13 times the exit diameter De, and with an elliptical profile. Although the investigations are not presented here, the corner radius Rc can be usefully designed as 0.08 times the entry diameter Di.


That's the juicy part of that whole article. though they do admit that the difference is as small as 1.5hp per 100....


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## Jettaboy1884 (Jan 20, 2004)

*Re: (notso2slo)*

Here's a good site to bump this back up:
Peak Torque Calculator, accounting for runner diameter:
http://www.rbracing-rsr.com/runnertorquecalc.html


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## Jettaboy1884 (Jan 20, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

Came across a pretty good article on Backpressure:
http://www.uucmotorwerks.com/h...h.htm 
And here's a similar article from Magnaflow:
http://www.magnaflow.com/07tec...0.asp 


_Modified by Jettaboy1884 at 12:29 PM 3-14-2010_


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## ny_fam (Apr 3, 2004)

*Re: (Jettaboy1884)*

I find that intake runner calculation problematic.
So much depends on the head work, and the head work depends on the angle of approach to the valve. For instance the crossflow heads have a steep angle, some serious work is needed for the air to make the turn. These ports have a lower diffusion coefficient. Where the counterflow has a higher discharge coefficient, and will require different cross sections than the crossflow even for the same size valves..
Then based on the port in the head you can determine the intake runner diameter and its taper.


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## notso2slo (May 1, 2006)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Jettaboy1884)*

That first article basically states that as long as your car can adjust for leaner conditions, then the less back pressure, the better... But I've personally gone from a 2.5in exhaust that was too big for my car (stock 2.slo) to an identical (same brand muffler and exhaust company) 2.25in, and felt better lower end response.
So is that just imagined response, or is that article only partially true?


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## chippievw (Dec 5, 2006)

*Re: (Jettaboy1884)*


_Quote, originally posted by *Jettaboy1884* »_
Interesting. http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 


I said that yrs ago, and everyone laughed....(not on here)


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## Lord_Verminaard (Apr 6, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (notso2slo)*

That backpressure article is only partially correct.
In reality, you never want backpressure, EVER. Backpressure, by definition, is the resistance of gas flow out of the engine. ANY backpressure in the exhaust, WILL HURT POWER. Period.
Where people get confused is mixing backpressure with exhaust velocity. There are a lot of factors involved with exhaust velocity- not just size, but shape of the bends, (why smooth, mandrel bends are GOOD) transition shape and length, merge collectors, even muffler design. (why baffled mufflers are bad for making power) What happens when people put much larger exhausts on engines that don't need it, is that exhaust velocity goes way down- the lower the velocity, the less power (more noticeable in low-rpm conditions) you will make due to the reduced cylinder scavenging effect. There could be very little backpressure in a large exhaust, but the gas flow is very slow so you are not gaining anything and the engine even has to work a little harder to get the exhaust gas out, which is why people can burn valves with huge exhaust. The smaller exhaust moves the gasses more quickly, so you make more power. OEM manufacturers use the smallest exhaust they can get away with which makes the cars perform much better at lower RPM were 90% of your average person drives their cars. Exhaust manufacturers try really hard to maximize both areas- keeping velocity up so the car is drivable, while opening it up enough to improve power at upper RPM's. Sometimes it's not an easy job.
Turbo cars are a completely different ballgame- you want the gas away from the turbine wheel as quickly as possible, it's already done it's job (spooling the turbo) so it's not needed anymore. There is no real scavenging effect once EMP builds up. (and most turbo manifolds aren't built for cylinder scavenging but rather minimizing spool time) That's why turbo cars in a race situation usually just have one very large pipe out of the turbo that goes about 2 feet out of the engine bay and ends there- out of the fender, or right behind the front wheel.
So repeat after me: YOU NEVER WANT BACKPRESSURE. VELOCITY IS KING!!!








Brendan


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## [email protected] (Sep 18, 2005)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Lord_Verminaard)*

I completely agree with the above, velocity is the key.
so that being said, Im building a new exhaust for my all-motor 16v race car. Using a TT race header as the base to build it, im going to smooth out the roughness in the collector, still use a 2.25in collector, then use a 2.25-4in megaphone, then run a short section of 4in pipe to make it exit out the pass side in front of the rear tire. mainly, just becuase i dont want the exhaust to exit under the car. Thoughts on this setup?
currently im running a full TT 2.25in exhaust with no res. just a borla muffler.


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## shannonekermans (Oct 9, 2007)

so wanted to try bring this back from the dead. but earlier it was mentioned about building a oversquare vw to rev. well i live in south africa and our current 1600cc motor is a 77mm stroke with 81 mm bore. what od you think it would take to get this thing to handle high rpms and what would its capabilities be like? i presume solid lifter head would be in order but rods? bolts etc? and what type of rpm can a stock solid lifter handle?


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## chippievw (Dec 5, 2006)

*Re: Let's Talk about making Naturally Aspirated Horsepower (Lord_Verminaard)*


_Quote, originally posted by *Lord_Verminaard* »_That backpressure article is only partially correct.
In reality, you never want backpressure, EVER. Backpressure, by definition, is the resistance of gas flow out of the engine. ANY backpressure in the exhaust, WILL HURT POWER. Period.
Where people get confused is mixing backpressure with exhaust velocity. There are a lot of factors involved with exhaust velocity- not just size, but shape of the bends, (why smooth, mandrel bends are GOOD) transition shape and length, merge collectors, even muffler design. (why baffled mufflers are bad for making power) What happens when people put much larger exhausts on engines that don't need it, is that exhaust velocity goes way down- the lower the velocity, the less power (more noticeable in low-rpm conditions) you will make due to the reduced cylinder scavenging effect. There could be very little backpressure in a large exhaust, but the gas flow is very slow so you are not gaining anything and the engine even has to work a little harder to get the exhaust gas out, which is why people can burn valves with huge exhaust. The smaller exhaust moves the gasses more quickly, so you make more power. OEM manufacturers use the smallest exhaust they can get away with which makes the cars perform much better at lower RPM were 90% of your average person drives their cars. Exhaust manufacturers try really hard to maximize both areas- keeping velocity up so the car is drivable, while opening it up enough to improve power at upper RPM's. Sometimes it's not an easy job.
Turbo cars are a completely different ballgame- you want the gas away from the turbine wheel as quickly as possible, it's already done it's job (spooling the turbo) so it's not needed anymore. There is no real scavenging effect once EMP builds up. (and most turbo manifolds aren't built for cylinder scavenging but rather minimizing spool time) That's why turbo cars in a race situation usually just have one very large pipe out of the turbo that goes about 2 feet out of the engine bay and ends there- out of the fender, or right behind the front wheel.
So repeat after me: YOU NEVER WANT BACKPRESSURE. VELOCITY IS KING!!!








Brendan

Its depends. Back pressure can stop over scavenging at the point of valve overlap. This is useful at times but not every time. http://****************.com/smile/emthup.gif


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## EL DRIFTO (Jul 11, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (chippievw)*

corky bell - back pressure is evil
kinetic energy is exponential - v*2
i've seen a 5.0 mustang pick up 1/2 second by pinching his open down pipes by driving over them twice, with a dually, @ the track 

here's a intake runner length calculator:

http://www.bgsoflex.com/intakeln.html


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## EL DRIFTO (Jul 11, 2004)

*Re: Let's Talk about making Naturally Aspirated Horsepower (chippievw)*

maybe a repost cant remember & somebody else posted it somewhere else
"When it comes to engine knowledge, this guy is cutting edge and goes against the grain of all the "accepted" theories. His bikes are the fastest on any cct he races. Can't argue with success.
http://www.mototuneusa.com/think_fast.htm
His break in secrets is awesome too, and just as controversial.
http://www.mototuneusa.com/break_in_secrets.htm "


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## Jettaboy1884 (Jan 20, 2004)

Bumping it back up. 

On a side note, Have a look at the amazing fabrication in this build thread: Alpha V6 into an E30 http://www.e30owners.com/forums/showthread.php?t=2435


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## Scorp67 (Apr 30, 2009)

shannonekermans said:


> so wanted to try bring this back from the dead. but earlier it was mentioned about building a oversquare vw to rev. well i live in south africa and our current 1600cc motor is a 77mm stroke with 81 mm bore. what od you think it would take to get this thing to handle high rpms and what would its capabilities be like? i presume solid lifter head would be in order but rods? bolts etc? and what type of rpm can a stock solid lifter handle?


  
Your talkingabout my engine  
Its true that it is under square which would suggest an abilty to rev higher due to lower piston speed BUT this is only if it was designed to rev high 
The 2.0 is over square and has a higher redline 
I hink the reason that the 1.6 ended us being undersquare is got to do with vw using the same bore across a few engines and just adjusting the stroke, and with the smaller capacity 1.6 it just worked out that way. 
Honda has a few motors which will rev happy with stock internals which are pretty over square, no way would i take mine to 7300 with stock internals 

Basically you could do it but the rods, bolts are not gonna cope in stock form, also the head is restictive, a fair bit more than the 2.0, smaller valve ect. so it will need work to get air in at higher rpm. 
Iv read on here about solid lifter heads reving up to 8k, and this rounds reasonable to me 

My R0.02


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## Jettaboy1884 (Jan 20, 2004)

Might as well bump this back up after a while of inactivity.

Found this cool thread on M42 club (BMW 1.8L twin cam) forum about resonant intake and exhaust tuning in practice:

http://www.m42club.com/forums/showthread.php?t=11944&highlight=short+runner+intake


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## tdogg74 (Mar 1, 2002)

I'll just put this right here....

http://forums.vwvortex.com/showthre...Excel-sheet-for-Intake-manifold-runner-length.


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## Jettaboy1884 (Jan 20, 2004)

I've really got the bug to build up a naturally aspirated 24v V6... It's a toss-up between the Yamaha SHO engine (older technology, but the leader in it's day), or the Honda J32A2... I've researched and ruled out the 2.5/3.0L Duratec, and the Mazda Kl-series...

Anyone have any suggestions? BMW or Toyota I-6 doesn't really appeal to me...

Ohh, and Here's another good article on cylinder heads:

http://www.austincc.edu/wkibbe/headdesign.htm

I'll have to take a bit of time and bring all the article links up to the first post in the thread...


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## Ls1Mx5 (Jul 28, 2010)

Jettaboy1884 said:


> I've really got the bug to build up a naturally aspirated 24v V6... It's a toss-up between the Yamaha SHO engine (older technology, but the leader in it's day), or the Honda J32A2... I've researched and ruled out the 2.5/3.0L Duratec, and the Mazda Kl-series...
> 
> Anyone have any suggestions? BMW or Toyota I-6 doesn't really appeal to me...
> 
> ...


Why not the Mazda Kl? People take those to 10-11000 rpm with itb's and cams. Their 1000cc sportbike like rod stroke ratio and internally balanced forged crankshaft allow them to naturally rev high without stratospheric piston speed and accelerated wear. Maybe this video will change your mind

http://www.youtube.com/watch?v=AACd9YZlh5E
(ignore the music and listen to that f1 sound)

Also take a look at this:

"Just to stir the pot in the best of Mazda's naturally aspirated motors , here's the dyno and a few pics of the motor if you didn't see it in the link posted in the other thread.... Dynojet SAE 253whp @ 8400rpm/178ftlbs @ 6100rpm

I found out more info as well.... it just amazes me he's making that kind of power with the following 

KL V6 2.5l with stock (unported) HLA KLZE 'Square-port' heads 
Interprep 9.4mm/280 cams
Interprep springs 
Custom Wiseco pistons 
Ford rods
Hayabusa throttles with velocity stacks
Electromotive stand alone tec 3 fuel and spark 
Old Ebay short runner headers 1.5" primaries with new custom down pipes
Open exhaust 
External oil pump 

Look at that flat torque curve, with 'mild' cams - by Honda standards... And revving to 9000rpm with hydraulic lifters?!?"

http://forum.miata.net/vb/showthread.php?t=287031


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## 02vwgolf (Oct 6, 2009)

This honestly is the most informative and one of the best threads i have ever read on vortex...im in the middle of a mk4 n/a 8v build and i want to thanks everyone who has contributed to this i just learned more here then i ever may have learned in school:laugh:


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## sauron18 (Apr 11, 2009)

I'm thinking of going 2.0 20v what compression is better for me with 91oct? i'm thinking of 10:5 or maybe 11:1 but don't know if that would be safe and 82.5mm pistons or maybe 83mm. I want it to be streetable and daily don't care about a lot of power but fun to drive.


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## 16v Drakes (May 26, 2008)

*USf3*

I have a mk2 golf 1680lb.............has anyone run that usf3 motor in a golf..............Race car only .......fuel VPQ16


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## victor18 (Apr 14, 2020)

*Re: Let's talk about making naturally aspirated horsepower*

Thank You,

Firstly thank you for the information . The links have been more then helpful with my personal projects. Looking forward for your next article . Those articles were just what I was looking for .


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