EB338

I know this topic has probably been discussed before and if this post is redundant I apologize. Are all 32v heads created equal? If not which are the best candidates for modified engines? (model years and part numbers if possible) Which can take the most porting, have the biggest valves, etc. What changes were made to these heads over the years?? Is there a difference between US and Euro 32v heads like there is in the 16v heads?

Thanks

Vilhuer

AFAIK there are four different versions of the heads.

1. '85-86 US and '86 ROW Kat model 32 valve S
- 35mm intake and 32mm exhaust (small) valves

2. '87 to early 89 S4, CS and SE, used worldwide
- 37mm intake and 34mm exhaust (large) valves
- Combustion chamber design is different shape than in 32V S
- More wide front bearing area in cam journal
- These were used up to engines 81K 00120 (5sp) and 81K 05238 (automatic), K = '89 model year

3. '89 to '91 S4, CS and GT, used worldwide
- Introduced starting from engines 81K 00121 (5sp) and 81K 05239 (automatic)
- 20mm thicker area under bolts, this should be good for boosted applications
- Same combustion chamber and valves as 2.

4. '92-95 GTS, used worldwide
- Different water flow holes on exhaust side, improve cooling
- Same combustion chamber and valves as 2.

Later is better and at same time harder to find.

tammons

I was told that the early 4v heads will drop the compression on an S4 engine, but I have never verified it.

Vilhuer

Gaskets are different also but they can be used with earlier heads.

S4 pistons + 32V S heads should give around 8:1 compression ratio
32V S pistons + S4 heads result very high comp ratio, around 12-13:1 IIRR

jyoon

is there any difference in the 86.5?

tammons

I think that the 86.5 heads are the same as 85-86. I actually have a set up bent valve heads I want to sell, but they are still on the motor.

Jim bailey - 928 International

The 85-86 heads engines are identical (with the exception of the GREEN option lower compression Euro 32 valve with cats ) The designation 86 1/2 is somewhat miss named since what really happened was the first 1000 USA "1986" cars and NOT EURO cars basically were built to 1985 specifications.

Rick Carter

Getting back to your question; what engine modifications will you be doing, what heads do you currently have, forced induction or NA, what is your budget? What is the final goal?
Rick
85 32v

blau928

Has anyone done any calculations or have data on what Compression Ratio would be yielded from the following:

S4 Block
85-86 32V heads Ported and cut to accept 968 Valves
95.25mm Stroker Crank

Thanks,

DFWX

According to Devek, 85/86 heads on an S4 makes 8-1 compression.
Mark
DFWX

EB338

I assume the whole cam housing setup is the same regardless of year? (I know the cams themselves aren't the same) Also since we are on the topic, what about the 32v intake manifolds? Is later better there as well? Some take more modification than others, etc.?