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By Dawid van der Walt
#103288
Hi guys.
Peeking over the wall :hiding: from the other side. Thought I'll start with a question.
How do I tell which heads is on my 87 s4? 1R or 2R -5R?
I have just removed the heads and is learning and evaluating what my next steps are.
Both heads are within the warpage limit, and one have a rather bad pit that does not appear to close to the fire ring. Will have them soda-blasted and go from there.
Cheers
Dawid aka 545SVK
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By worf
#103342
I have two engines on stands, but they are complete and ready to 'drop in' so I can't get a good picture for you.

However,

... on the intake-side of the head, at the top inside 'lip' just below the cam cover sealing surface, in the vicinity of cylinder #2 and cylinder #7 intake ports, I do believe you will see a casting number with the following schema:

928.104.014.<X>R where <X> is 1,2,3, etc.
By Dawid van der Walt
#103578
Thanks. So I have 1R heads, with the numbers on the cam towers being 36 and 38 respectively.
Does the low numbers mean anything other than being low?
Did the '86 s3 - 5 liter with the organ pipe intake - use the same heads as the s4?
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By The Fat Man
#103695
No, the 1985 and 1986 S3 heads are different from the 1987 S4 and on heads. Larger combustion chamber, smaller valves, bolts for intake pipes instead of studs, older 2 stud exhaust port flange.

Supposedly, S3 heads will physically fit on an S4 block, but you wouldn't really be able to do anything with them. The larger combustion chambers would drop the compression ratio a considerable number.

And there aren't that many sets of S3 heads floating around. Only a 2 year thing. And, reading the Tech Spec books for 1985 and 1986, there are detail differences in the 1985 vs 1986 heads.
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By worf
#103762
Dawid van der Walt wrote: Sat Sep 11, 2021 1:11 am Thanks. So I have 1R heads, with the numbers on the cam towers being 36 and 38 respectively.
You refer to the numbers stamped into the exhaust-side of the head, in the middle just below the cam cover sealing surface?

Technically there are no cam towers on the 32v heads. The term pertains to the 16v motors where the single cam for each bank is enclosed in a housing that bolts the 16v head.

Dawid van der Walt wrote: Sat Sep 11, 2021 1:11 am Does the low numbers mean anything other than being low?
If the answer to my question is 'yes', then those numbers are used to match the cam caps and cam bridges to the head. Each cam cap and bridge is stamped with that number. The caps are also stamped with the bearing number as is top surface of the head adjacent to the outboard threaded cam cap hole.

Dawid van der Walt wrote: Sat Sep 11, 2021 1:11 am Did the '86 s3 - 5 liter with the organ pipe intake - use the same heads as the s4?
Same basic 'raw' casting I think. But as @The Fat Man notes all of the detailed machine work and other bits is non-trivially different.
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By worf
#103763
BTW, what I described above is clearly described in the WSM.
By Dawid van der Walt
#103887
Thanks Worf - I did not ask my question, "Does the low numbers mean anything?" clearly.
What I meant was, is the fact that the numbers are so low, 36 and 38, of any interest. Are they some of the first heads cast, or something similar?
I do not have the build sheet or early history for my car, but a friend of mine has a s4 with a '86 build date, with higher head numbers than mine.
So I am wondering how early an s4 mine might be.
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By worf
#104096
Dawid van der Walt wrote: Sun Sep 12, 2021 6:38 pm What I meant was, is the fact that the numbers are so low, 36 and 38, of any interest. Are they some of the first heads cast, or something similar?
The WSM calls it a "pairing code." I've had engines with hears where one side was 3x and the other side was 9x.

I think it is exactly what the WSM calls it: a pairing code and that it has no significance beyond that.
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By oups59
#104983
From my 1988 S4 heads
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Panorama September 2021

great representation ~!