[s-cars] Audisport aluminum blocks

[QSHIPQ at aol.com]

James:
I've watched your posts over the last year with interest.  At this point, I 
see that some of the suggestions made by others have hit home, others not.  I'm 
going to toss out a few suggestions.  First, get a library of audisport 
stuff.  There is a lot of material out there on what works and what doesn't.  IMO, 
the first that comes to the list of "doesn't" is the use of the aluminum 
block.  I wouldn't spend a dime on it.  Helicoiling (Tymesert please) an aluminum 
block is a one shot deal, and really requires (ask any mercedes pro) a deck 
plate.  I doubt there are more than a handful of those in the US, if that many.  
Before I'd work an aluminum block, I'd have deck plate in hand, and have a 
confirmation that what you "think" is right (inserts), is.

If your goal is to keep the aluminum block, I'd ship the whole thing off to 
Lehmann or some other shop very familiar with it.  I'd also suggest a detailed 
read of the problems Audisport, Lehmann, Beddor, et. al. had with it.  It's 
pretty well known that for the 50lb weight savings, you can create more problems 
than you solve when adding power.  First, know that high boost levels and 
aluminum blocks don't work in harmony.  They never did.  Certainly comparing one 
to the cast iron block, the boost levels achieved without the ARP studs are 
pretty dramatic, even at 9.3:1 CR.  And the blocks are quite common.  And these 
blocks put down 400hp levels quite easily and longterm with bolt on "RS2" 
modifications.

With regard to your low HP levels, you really need to find a shop that can 
help you.  You once shared with me, this problem has plagued this project since 
before Bruno, so I'm betting you need to find someone that can figure this 
out.  Drive it, ship it, deliver it somewhere.  Using *any* of these lists will 
get you free opinions, and a plethora of them.  But bottom line is, I'm reading 
of modifying an aluminum block, which sounds an alarm in my head, something's 
not right, and I'm betting it still won't be when you are done.  Or worse.

One thing I would ck before I did much else is the code vs the pin 
location/pickup on the flywheel.  I've seen several times over the years, that 
audisport/Lehmann have moved the locations of the timing pins fore and aft, which could 
dramatically affect driveability and actual power output.  

You also need to make some hard choices here in terms of what approach you 
are taking to this project.  Since this won't be and never was an audisport car, 
I'd sure consider putting in the improvements that made the 20vt one of the 
best audi production motors to date.  The formula for 400hp is pretty well 
documented on this list, and certainly has shown it's day to day longevity.  
Audisport cars were handbuilt test mules, each and every one was slightly 
different.  I wouldn't hesitate at all to make the improvements to it, just do it in 
the spirit and intent of all audisport machines: make it simple, easy to 
service, and bulletproof as possible.  BTDT.

A period spec rally car is a covetted piece of audisport history, original or 
Bruno copy.  That sure wouldn't in any way deter me from putting in the 
standard "S-car" formula for the HP equation.  I'd certainly take a stock AAN motor 
and harness swap, before I'd touch my wallet trying to 'fix' the aluminum 
block/3B setup in any way.  The side benefit is, everything you have that 
attaches to one, attaches to the other.  Then just put a sticker under the hood "no 
magnets", to match the one by the fuel door "no smoking".

HTH and my .02

Scott Justusson
QSHIPQ Performance Tuning
'83 Urq
'84 RS2URQ Project
'91 v8