# 20v NA hybrid high profile race engine build



## nascar2014 (Mar 12, 2011)

High Profile Project - MK1 VW Rabbit circle track build - Need everyone's input 

*OUR PROJECT *To build a dominating circle track VW Rabbit . . in 30 days!

I NEED YOUR HELP!!!! Nothing is set in stone and everything is open for debate. I believe everything can be reduced to a number and best number is best choice. What I'm trying to say is I have no pride of authorship here, I want to build the best possible motor for our application and all who contribute will be credited! 

This first post will encompass all components and processes of the build in a very clear format. I want and need everyones input . . but please quantify your input . . ie. this part would be better because . . 

The following few posts will outline things like our rules for the engine and car, the visibility of the project, our driver and other information that might be useful or interesting to everyone.

*ENGINE SPECIFICATIONS*
target HP - TBD (highest possible within our set of rules)
target RPM - 9,000+
bore - 83.0mm reason - to unshroud the valves as much as possible.
stroke - 80mm reason - oversquare to promote a more reliable hi revving engine
rod length - 136mm reason - 1.7 rod/stroke ratio

*FUEL*
114 90% ethanol
reason - rules are open to race fuel, ethanol burns cooler which allows for more timing advance, ethanol by formula gives approx a 9% increase over regular race fuel

*ENGINE BLOCK*
AEB vs AEG vs 1.7 vs ?

*CYLINDER HEAD*
1998 AEB 20v
reason - highest stock flowing head in 4 cyl lineup
mods - possible raised seats to unshroud the valves, bronze short tapered valve guides

*CRANKSHAFT*
My primary decisions are distributor vs CPS and IM vs chain driven oil pump, which will give more direction here. My initial preference would be CPS with chain driven oil pump but I could be totally wrong on this. 

*CONNECTING RODS*
Audi 1.6L 136mm forged rods
reason - the strongest 136mm rod in the lineup
mods - ARP Bolts, polished beams, matched and balanced

*INTAKE MANIFOLD*
I haven't made much progress here.
looking at stock AEB turbo manifold and 99-05 Golf GTi 20V turbo 2.0L. I have heard the AEB manifold with its front mounted throttle body works well on a normally aspirated engine but have seen no data to support this other than forum hearsay. It would seem that the stock AEB manifold might flow best just because it has larger runner ports that match the AEB head.

*EXHAUST MANIFOLD*
VW GOLF MK4 1.8 20V NA AGN
reason - best flowing manifold in lineup
mods - none


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## nascar2014 (Mar 12, 2011)

*RULES - Engine and Transmission*

I am posting these rules merely to show how vague they are. We have raced in this division and are very familiar with what is legal, what is grey matter, what is overlooked, what is enforced and what will get you disqualified.

Thank you for early concerns, but our car and engine choice is completely within the guidelines of the rules. I need input from everyone and will decipher the legality of contributions.

*Engines & Transmission:*

1. Only four or six cylinder naturally aspirated engines will be allowed. No rotary engines. Only the complete stock engine for the make and model as delivered from the factory may be used.

2. All 6 cylinders may utilize only one cam per head. V-6’s must run an automatic transmission.

3. Stock intake manifold must be used with no modifications.

4. Stock exhaust manifold must be used with no modifications. No Headers, even if delivered from factory. EXCEPT: GM 3.8 liter V-6 may use factory header. Removal of smog, emission, air conditioning, and power steering parts are permitted.

5. A complete exhaust must be in place completely under vehicle. No portion of exhaust may pass through interior and must exit under vehicle behind the driver. Removal of catalytic converter is allowed.

6. Cars with engines utilizing Dual Over Head Cams or more than 1 cam may NOT have exhaust that exceeds 1.5” in diameter. All other cars must utilize exhaust with 2” diameter maximum. The exhaust system must be completely sealed and the maximum diameter must be utilized in at least the last 24” of the exhaust pipe.

7. Must use stock style starter. Battery may be relocated to an area behind driver. If so it must be secured & covered.

8. Transmission must remain stock and unmodified for that vehicle’s production. Transmission must have working forward and reverse gears.


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## need_a_VR6 (May 19, 1999)

nascar2014 said:


> *Engines & Transmission:*
> 
> 1. Only four or six cylinder naturally aspirated engines will be allowed. No rotary engines. Only the complete stock engine for the make and model as delivered from the factory may be used.


Which Mk1 has a 20v stock?


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## ps2375 (Aug 13, 2003)

Are these rules for US market or does it allow for Euro/JDM models "as delivered"? And with this line "Only the complete stock engine for the make and model as delivered from the factory may be used.", how do you propose to use the 136mm rods w/ a 20V head? And there was no non-turbo 20V motor brought to the US, what "stock" exhaust mani are you going to use? That rule doesn't sound like you'll get past the first protest of your motor, as it doesn't sound as it allows you to mix and match motor components.

I don't want to rain on your parade, but I also would hate to see you waste money and time on a build that would be deemed illegal by sanctioning body.


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## nascar2014 (Mar 12, 2011)

Rules specify the engine has to have come in that make and model, not the specific year of car being used.

Mixing and matching of components are promoted in this class. Foreign cars and engines are permitted.


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## ps2375 (Aug 13, 2003)

So, that means non-US market models allowed? If so, that is good, but a 30day time line on parts never brought to this market seems kinda tight.


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## MonkeyBusiness (Jun 11, 2009)

Have you already sourced the intake and exhaust manifolds? they could be very difficult to get your hands on


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## nascar2014 (Mar 12, 2011)

ps2375 said:


> So, that means non-US market models allowed? If so, that is good, but a 30day time line on parts never brought to this market seems kinda tight.


Yes, the rules arent clear but we have been thru tech with nissan and hondas that fall into this same situation.

Thirty days makes me cringe, but I dont think they will hold up the first race for us! lol I am not sure where I am going to have problems getting parts yet, but rest assured, I'm sure Murphy will point it out!


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## nascar2014 (Mar 12, 2011)

*Intake and exhaust manifolds*



MonkeyBusiness said:


> Have you already sourced the intake and exhaust manifolds? they could be very difficult to get your hands on


AGN exhaust is on its way. With no mods, were in good shape on it. Plus I have 2 high priced ones available if need be.

Intake hasn't been settled yet. I have the AEB turbo manifold and a Passat log manifold on its way. Not sure of the best direction NA. Have heard mixed unsupported comments in many directions on the intake.


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## ps2375 (Aug 13, 2003)

Well GL with build and keep us posted on how it goes.


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## nascar2014 (Mar 12, 2011)

*Engine Block*

Considerations

*IM shaft vs chain driven oil pump*
The engine is going in an MK1 so the external water pump block makes mounting easy. I am not aware of any external water pump blocks that have a chain driven oil pump. If the chain driven pump would be better for high rpm, then we can easily fab the mounting brackets.

*Distributer vs Crank position sensor*
I definitely prefer the crank position sensor but am not sure how to get there with an 80mm crankshaft. Somebody correct me if I'm wrong but I don't believe any 80mm cranks came with a reluctor wheel. I am aware of the VW Polo rear crank seal trigger but haven't been able to contact anyone that actually has it working

*Bore*
Our target is 83mm but this is an arbitrary number based on largest safe bore in an effort to unshroud the valves as much as possible.


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## nascar2014 (Mar 12, 2011)

ps2375 said:


> Well GL with build and keep us posted on how it goes.


Thanks! I will start posting pics tonight. The car is a hybrid in itself! Cabrio with 4dr roof section!


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## need_a_VR6 (May 19, 1999)

You'll want some real cams in it too. 

Also why so small on the stroke, you displacement limited?


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## nascar2014 (Mar 12, 2011)

need_a_VR6 said:


> You'll want some real cams in it too.


Yes, going with a solid lifter setup and planning on having cams reground. From a rules standpoint, I know there are several cars with aftermarket camsin our division but I am planning on reground shafts to be safe, unless I can't achieve the needed profiles. Would appreciate any direction as to a good cam grinder(s) that I can start discussing this project with.




> Also why so small on the stroke, you displacement limited?


I have been running profiles on engine simulator and this combination shows a definite advantage. Several rally and road racing VWs and Audis are running an 83mm bore with 80mm stroke with great success. This info isn't widely publicized but I have had it confirmed by a couple reputable individuals here in the forums.


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## need_a_VR6 (May 19, 1999)

I would talk to WEB they don't have their heads in their rears like some others. However getting something on the quick, especially ground solid might be tough.

Simulate what you want but the bigger cranks are newer, readily available and will give you a bigger powerband...


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## nascar2014 (Mar 12, 2011)

need_a_VR6 said:


> I would talk to WEB they don't have their heads in their rears like some others. However getting something on the quick, especially ground solid might be tough.


I will give them a call immediately. Thank you.



> Simulate what you want but the bigger cranks are newer, readily available and will give you a bigger powerband...


I definitely see your point with the availability of new cranks. As for the powerband, we only need about a 2,200RPM window. In talking to people who have spun the 92.8mm stroke cranks upwards of 9,000, they have had oil heating problems. This problem might have an explanation and a cure, I just haven't investigated that direction.


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## createddeleted (Sep 24, 2008)

I figured I would post this for as interesting as it sounds.

http://www.racecarsdirect.com/listing/33669/JRE_2000_8v_VW_Golf_engine_212bhp.html



> JRE built 8v VW Golf engine producing 212bhp for autograss/ rally/ race, ultra big valve head, ultimate steel rods, forged pistons, full stainless steel JRE exhaust manifold, jenvey throttle bodies, DTA ecu, brand new built and dyno run ready to fit.


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## need_a_VR6 (May 19, 1999)

nascar2014 said:


> In talking to people who have spun the 92.8mm stroke cranks upwards of 9,000, they have had oil heating problems. This problem might have an explanation and a cure, I just haven't investigated that direction.


You won't need to spin that high with a big crank in the motor. Hp will be the same but over a wider area and lower rpm when you get head/cam limited. Just gear it right. 

Here's a built na 20/20... don't mind the jitters we had ignition problems.


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## nascar2014 (Mar 12, 2011)

I know the undersquare design of the VW engine produces decent power. Virtually everyone uses the stock geometry and gets what they get. I want to know who has actually built a short stroke 20v engine and what the results were.


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## nascar2014 (Mar 12, 2011)

From a trigger standpoint, if I use an older 80mm crank, the VW Polo crank seal trigger would simplify the install. Is there anyone who has made it work with a MS system?


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## ps2375 (Aug 13, 2003)

I would think with a 30 day deadline, you would go with what has been proven and "re-invent the wheel" over a longer time line. Not knowing your resources, that would seem to make more sense, as it seems you will be waiting for parts more that working on it.


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## nascar2014 (Mar 12, 2011)

ps2375 said:


> I would think with a 30 day deadline, you would go with what has been proven and "re-invent the wheel" over a longer time line. Not knowing your resources, that would seem to make more sense, as it seems you will be waiting for parts more that working on it.


Yes, 30 days isnt much time at all. I am collecting parts for both an 8v and a 16v build also but those motors are pretty much boiler plate builds. The 8v will def be used at at least 2 tracks this season and the 16 will be at minimum a backup. The 20v build is for a very fast 1/2 mile track. Corner entry speeds are right around 115mph.

Block selection is my next big issue. I have 2 shops on standby to bore, hone, linebore and whatever else might need to be done to the chosen block. I can only imagine getting thru all the obvious road blocks, only to be held up for a head gasket or some other last minute need.


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## need_a_VR6 (May 19, 1999)

nascar2014 said:


> I want to know who has actually built a short stroke 20v engine and what the results were.


You might have to build it yourself to find out. IMHO that wouldn't be my first choice.

I helped NLS try and get an actual 16v Polo motor run with that sensor installed, and we didn't have any luck. It could have been a bum stock sensor but we ended up with an 18-1 on the serp pulley.


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## nascar2014 (Mar 12, 2011)

*VW Polo crank trigger with MS*



need_a_VR6 said:


> I helped NLS try and get an actual 16v Polo motor run with that sensor installed, and we didn't have any luck. It could have been a bum stock sensor but we ended up with an 18-1 on the serp pulley.


I have been thinking about the possible problems why it doesn't seem to be working. With all the settings for the MS, I am wondering if possibly the waveform from the sensor is different than what people are setting. I have an oscilloscope and was gonna check its output. Do you still have a unit? Or do you know where I can get one?


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## nascar2014 (Mar 12, 2011)

need_a_VR6 said:


> You won't need to spin that high with a big crank in the motor. Hp will be the same but over a wider area and lower rpm when you get head/cam limited. Just gear it right.
> 
> Here's a built na 20/20... don't mind the jitters we had ignition problems.


What was in this motor? bore, stroke, head, intake, exhaust,, ecu, mods? Is that engine or wheel hp?


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## MonkeyBusiness (Jun 11, 2009)

here is the build thread

http://forums.vwvortex.com/showthread.php?2580034-Project-ABE-(AEB-ABA)-110-HP-L

It's an ABA with an AEB head. He's running ITB's and a custom made header. The dyno graph is at the wheels


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## need_a_VR6 (May 19, 1999)

MonkeyBusiness said:


> here is the build thread
> 
> http://forums.vwvortex.com/showthread.php?2580034-Project-ABE-(AEB-ABA)-110-HP-L
> 
> It's an ABA with an AEB head. He's running ITB's and a custom made header. The dyno graph is at the wheels


Yeah that thread, enjoy. We could probably have made more power on different fuel, that's on 93 octane.

I think if I had a NEW sensor it probably would have worked. It's just a 60-2 hall, I do hall all the time and 60-2 VR all the time so there should be no inherent issue with the setup.



> Do you still have a unit? Or do you know where I can get one?


What unit?


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## [email protected] (Jan 2, 2009)

I would do the 144 x 20 / 92.8mm and as much compression as you can get. The center intake valve notch limits the cam lift on that valve, which sucks. Get them to make the center intake valve notch as big as you can and then run a mechanical lifter head with the centerlines LOW. 

If you must have the ~1.7 rod ratio, use an 86.4mm crank with the 144 rod. That's a 1.66 r/s ratio, available off the shelf (FAST) and the piston won't be stupid. The 80mm / 136 combo will give you a very heavy and tall piston. 

The 92.8 cranks make more power then the 86.4's, with the same rod and deck, I wouldn't think going to an even smaller crank would suddenly reverse that trend. :thumbup:


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## MonkeyBusiness (Jun 11, 2009)

http://www.bildon.com/catalog/DetailsList.cfm?ID=9270DA&Nav=6&SubNav=62

here are some pistons but you could get some custom pistons made with a higher compression ratio


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## [email protected] (Jan 2, 2009)

I was just talking to JE, on a stockish bore, with the 86.4mm crank about 11:1 is the best you can do, with the bigger crank, you can get almost 13:1. 

So there's another reason.


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## need_a_VR6 (May 19, 1999)

... and a good reason it is.


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## nascar2014 (Mar 12, 2011)

need_a_VR6 said:


> What unit?


A VW Polo crank seal trigger system.


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## need_a_VR6 (May 19, 1999)

nascar2014 said:


> A VW Polo crank seal trigger system.


If I had a spare I would have tried it on that Polo motor instead of going crank trigger.... so, no


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## 75injectedSB (Feb 6, 2006)

I vote 92.8 or 86.4 crank as well. No real reason to run the old 80mm crank and 136 rods. Running a much more available 86.4mm crank and dime a dozen 144mm rods seems like a better alternative. Going that route will put you very close to the 1.7 R/S ratio you want.

80mmx136mm=1.69

86.4mmx144mm=1.66

92.8mmx159mm1.71

As you can see above, you could run obd1(forged, strongest of the bunch and everywhere)aba rods and crank and be right where you want to be. Pistons for the 20v head on an aba block are readily availabe as well. No waiting for parts. But if you must, please be different.


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## sdezego (Apr 23, 2004)

I have to agree with ^. 

If the Rod ratio is what you are after, then the 2L OBD1 ABA @ 1.71 is where it's at and tried and true. Readily avail for cheap, forged crank, oil squirters, factory Forged rifle drilled rods, block can go to 83mm no problem, variety of Headgaskets are off the shelf and ready to go, pistons are easily attainable and maybe even off the shelf, respectable 21mm wrist pins, etc, etc.


..unless you really have to have a 1.7 R/R with a big bore (relatively speaking)


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## Rosten-Performance (May 15, 2010)

*6. Cars with engines utilizing Dual Over Head Cams or more than 1 cam may NOT have exhaust that exceeds 1.5” in diameter. All other cars must utilize exhaust with 2” diameter maximum. The exhaust system must be completely sealed and the maximum diameter must be utilized in at least the last 24” of the exhaust pipe.*

The exhaust size restriction seems like a major PITA if you plan to use a 20v head.
Easiest/fastest way to build an engine for this class would be a ABA

Also regrinding 20v cams are not any success,these cams are only surface hardened (not sure what the english word for that is)
So regrinding them require a full hardening process which is expensive and time consuming.

80mm stroke and 136mm rods needs hopeless heavy pistons,and it is difficult to get any compression at all with that small displacement with a 20v head

I assume ABA's are dime a dozen over there,bore it out to 84.50 or 85mm use the stock 159mm rods/stock 92.8mm crank and use the stock trigger wheel

Cams are also easily found for these engines


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## purple-pill (Feb 2, 2003)

Rosten-Performance said:


> *6. Cars with engines utilizing Dual Over Head Cams or more than 1 cam may NOT have exhaust that exceeds 1.5” in diameter. All other cars must utilize exhaust with 2” diameter maximum. The exhaust system must be completely sealed and the maximum diameter must be utilized in at least the last 24” of the exhaust pipe.*
> 
> The exhaust size restriction seems like a major PITA if you plan to use a 20v head.
> Easiest/fastest way to build an engine for this class would be a ABA


nothing says you can not have (2) 1.5" exhaust's


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## 16v Drakes (May 26, 2008)

purple-pill said:


> nothing says you can not have (2) 1.5" exhaust's


Was any motor ever built


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## nascar2014 (Mar 12, 2011)

*different direction*

Yes, but went an entirely different direction due to rule changes. Ended up with aba block 8v counterflow head off turbo, os valves with 7mm stems, titanium retainers, lightweight lifters, big hydraulic cam, lightened and knife edged diesel crank, scat rods and off the shelf 83mm weisco pistons from a different make engine that had thinner rings and was much lighter than the ones made for the VW. techtronics did the distributor, and has CIS mechanical injection.


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## 16v Drakes (May 26, 2008)

HI I sent you an IM


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