# High revving 8v questions



## NA 8v for life (Apr 11, 2007)

I am currently rolling around on a 1.9l JH with a 288* cam, diesel crank, blah bahl blah blah blah. Now I bought this motor from a friend and have pretty much fallen in love with the NA 8v's since I got it. But not I want to build my own and am wondering a few things.
My first question is what all do I need to accomplish this, I know serious lightening and balancing is going to be needed and HD valve springs to deal with the 306* I plan on running, but I dont know exactly what im looking for. On the TT site they have race connection rods and such, but they are asking 800 for those and that seems a little steep.
Im aiming for a 2.0 bored out to 2.1/2.2 that can rev to at least 7000 (I am aiming for 9000). This is my first serious motor build and I know there are things I am leaving out but thats why im here posting, so you can all flame me and tell me what to do


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## chois (May 12, 2000)

Those long stroke cranks are at odds with your high rpm goals. I suggest sticking with 1.8 crank, gain the ccs you can with larger pistons. You can get forged rods and pistons custom made from several sources. Pauter rods have a good reputation. A powerful NA motor is expensive.
My buddy runs a 9000rpm 8v in his race car, but it is a short stroke 1.5. Power peak is still down near 7k, but it does not fall off a cliff, so it can rev out when needed.
The biggest key that we found is great headwork. LR engineering at http://www.porttuning.com created a work of art that we bolted to the top of the motor.
You need to be sure you can flow the air needed for such a big cam - we do run a big cam in this motor, but due to class restrictions (stock valve size, stock throttle body butterflys) we have found it possible to overcam the engine.


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## NA 8v for life (Apr 11, 2007)

The motor is going to be running GSXR750 ITBs and have a full port/polish with larger valves so breathing shouldnt be an issue. It also looks like porttuning should be able to hook me up with the head I am looking for.
Is there any way I can still use the 2.0 block, the oil squirters in those blocks make me feel safer when revving, perhaps a 2.0 block with 1.8 crank? I think the audi 3a doesnt have as long a stroke as the ABA, I might be mistaken though. Plus a 2.1/2.2L sounds a little better IMHO than a 1.9 (which I already have).
Glad to hear my aspirations of revving to 9000 are practical though. Does running distributorless spark sound like a good idea if I want to be in that 9000rpm range, lots of things moving and I want my spark to be dead on.
Another question, is there any way to convert the 2.0xflow head to solid lifters so I can run a 306* in it?


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## ABA Scirocco (May 30, 2001)

*Re: (NA 8v for life)*

The 2.0L block is useable, you just need to make sure the pistons you get have the correct compression height for the crank and rods you're using. To do the calculation, add the compression height, rod length and half the stroke, the resulting number should be the same as the block height, for a 1.8 or 3A, the block height is 220mm, for the ABA it's 236cc. 
The ABA and the Audi 3A both have the same stroke of 92.8mm.
Converting a hydro head such as the X-flow head has been covered many, MANY times on these forums, try a search, all the info you need is there. But, since porttuning is doing a head for you, why not have them work out those details for you.


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## NA 8v for life (Apr 11, 2007)

*Re: (ABA Scirocco)*


_Quote, originally posted by *ABA Scirocco* »_Converting a hydro head such as the X-flow head has been covered many, MANY times on these forums, try a search, all the info you need is there. But, since porttuning is doing a head for you, why not have them work out those details for you.

Double good point. http://****************.com/smile/emthup.gif 
sounds like I still wont be able to use the 2.0 block though.. since I want revs and the stroke is the same in the 3a and the ABA


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## ABA Scirocco (May 30, 2001)

*Re: (NA 8v for life)*

For what you have in mind, the stroke of the 2.0L engine's not a limiting factor, either the 3A or the ABA can rev to 9000 although not quite as freely as a 1.8L. If you decide to good with a 2.0L engine, the ABA would be the better choice because of the higher rod/stroke ratio.


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## WackyWabbitRacer (Apr 24, 2001)

*Re: High revving 8v questions (NA 8v for life)*


_Quote, originally posted by *NA 8v for life* »_..... that can rev to at least 7000 (I am aiming for 9000). 

Without the air flow and a camshaft with a high rpm power band, the "spinning" of an engine to 9000 rpms can only wear out the components faster with no additional acceleration of a vehicle.
A peaky engine (i.e. one that makes its best power over a narrow rpm) needs to be matched with a gearbox with narrowly spaced ratios to produce its best acceleration.
It's the torque applied by the tires to the ground that actually accelerates a vehicle. For all practical purpose, as far as maximum automobile acceleration is concerned, all that really matters is the maximum engine torque imparted to the ground via the transmission ratios to the tires.
At 9000 rpms, most engines are way beyond their maximum torque range.
Cheers, WWR.


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## NA 8v for life (Apr 11, 2007)

*Re: High revving 8v questions (WackyWabbitRacer)*


_Quote, originally posted by *WackyWabbitRacer* »_Without the air flow and a camshaft with a high rpm power band, the "spinning" of an engine to 9000 rpms can only wear out the components faster with no additional acceleration of a vehicle.


Would GSXR750 ITBs and a 306* race cam be enough to accomplish this, I have the 288 in my rabbit right now and I beleive its powerband is 4-7k.
I have also been tossing around the idea of a NOS setup that only kicks in after 7k to help with the power up top. Although my experience with NOS is 0 so I dont know the pros/cons of this type of setup.
I think I am sold on the bored 2.0 aba block, P&P xflow head with solid lifters, TT's 306*, with MSNS distributorless ignition.


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## eurotrashrabbit (Oct 25, 2001)

*Re: High revving 8v questions (NA 8v for life)*

Its very expensive. And Jose at porttuning does great headwork 

















_Modified by eurotrashrabbit at 9:00 PM 5-17-2007_


_Modified by eurotrashrabbit at 9:01 PM 5-17-2007_


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## deer_eggs (Oct 4, 2006)

*Re: High revving 8v questions (eurotrashrabbit)*


_Quote, originally posted by *eurotrashrabbit* »_Its very expensive.

















it's also very pretty!!


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## NA 8v for life (Apr 11, 2007)

*Re: High revving 8v questions (deer_eggs)*

Im in no hurry, this is my project car. I got an 83 rabbit with a 1.9 8v to daily. 
Curious what you're running in that pic... looks along the lines of what I'm expecting.


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## eurotrashrabbit (Oct 25, 2001)

*Re: High revving 8v questions (NA 8v for life)*

13.5:1 2.0L 16v bottom end with a dish machined in them ABA obd1 head 1mm oversized valves 288 cam 45mm TWM throttle bodies


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## MkIIRoc (Feb 20, 2005)

*Re: High revving 8v questions (eurotrashrabbit)*


_Quote, originally posted by *eurotrashrabbit* »_Its very expensive.

















x2








I easily have over $3k in this motor, with the carbs, fuel system, etc, with all labor done by me to save costs. Not cost effective at all, but turns heads everytime I go to the track.


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## WackyWabbitRacer (Apr 24, 2001)

*Re: High revving 8v questions (NA 8v for life)*


_Quote, originally posted by *NA 8v for life* »_a 306* race cam be enough to accomplish this.

What is the quoted "power band" of this camshaft?
I am guessing you intend to use the Techtonics 306 camshaft with the following specs:
_TT Race Solid Lifter Cam 306°, .443" lift, 265° duration @ .050", 105 Lobe centers, Will work w/CIS, Chilled Harden billet. Will work with standard lifters. _
I may be wrong, but this 306 camshaft probably has a redline of about 7000 to 7500. Standard lifters would go into "coil bind" at 9000 rpms.
Again it is torque that accelerates the car; not extremely high rpms.
Good luck, WWR.


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## NA 8v for life (Apr 11, 2007)

*Re: High revving 8v questions (WackyWabbitRacer)*


_Quote, originally posted by *WackyWabbitRacer* »_What is the quoted "power band" of this camshaft?
I am guessing you intend to use the Techtonics 306 camshaft with the following specs:
_TT Race Solid Lifter Cam 306°, .443" lift, 265° duration @ .050", 105 Lobe centers, Will work w/CIS, Chilled Harden billet. Will work with standard lifters. _
I may be wrong, but this 306 camshaft probably has a redline of about 7000 to 7500. Standard lifters would go into "coil bind" at 9000 rpms.
Again it is torque that accelerates the car; not extremely high rpms.
Good luck, WWR.

Thats what I was thinking the issue would be, yeah I can rev to 9000rpms but after 7500rpms im just making more noise. Is anyone else running the TT306* in an 8v? curious to see how the idle/performance is.. im assuming worse idle with better top end performance.


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## SkunkWorks (May 18, 2007)

*Re: High revving 8v questions (NA 8v for life)*


_Quote, originally posted by *NA 8v for life* »_That's what I was thinking the issue would be, yeah I can rev to 9000rpms but after 7500rpms im just making more noise. Is anyone else running the TT306* in an 8v? curious to see how the idle/performance is.. im assuming worse idle with better top end performance.

Any high performance engine requires all internal components (crank, rods, pistons, intermediate shaft) to be fully balance.
Although the VW factory rods are excellent, your goal of a high rpm engine will need stronger rods such as Carrillo and lighter weight pistons. Lighter pistons pistons are more efficient because each time a piston changes direction it uses up energy to stop the travel in one direction and start it in another. The lighter the piston, the less energy it takes.
An automotive gas engine is an air pump where efficiency of intake & exhaust airflow is important as the performance factor increases. Without extensive cylinder head work, this efficiency will not be achieved. Obviously other factors are the intake and exhaust systems to get the air into the cylinder head and out of the head.
Although classified as a race cam, the TT 306 is a relatively mild race camshaft given the amount of lift, the usage of standard lifters, and the compatibility with the CIS fuel injection. Unless you can find the power band specs, it will not do much above 7500 rpms.
A more aggressive camshaft will require competition valve springs to prevent coil bind at high rpms.
Before getting too wrapped with 9000 rpm engines, you should have an objective for the amount of torque and horsepower. Then decide what engine components will reach that objective. Big numbers mean high dollars.
Skunkie....


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