Early S4 valve cover paleontology?
#1
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Early S4 valve cover paleontology?
Early set of S4 valve covers, casting date = 86, part # is 928 104 461 07, which is in between the -06 listed for 86 in PET, and -08 listed for '87. The curious thing is that there are 3 small holes on each cover. Anyone with an early '87 got any clue what these are for?
FWIW, pretty sure these are painted. my blast cabinet with girly man compressor is able (albeit slowly) to take these to bare metal. Not a chance on the 90, 91 and 93 covers I've had stripped.
FWIW, pretty sure these are painted. my blast cabinet with girly man compressor is able (albeit slowly) to take these to bare metal. Not a chance on the 90, 91 and 93 covers I've had stripped.
#4
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Compared to AO's early '87 production motor, the pattern for the plug wire brackets is different on the 1987 S4 engine brochure photo, I wonder whether those holes were for some stillborn plug wire brackets?
EDIT: Probably shoulda looked more closely before hitting 'post', I think I disagree with myself. Nevermind.....
EDIT: Probably shoulda looked more closely before hitting 'post', I think I disagree with myself. Nevermind.....
#5
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Something (not used) on the 1-4 side at the back, instead?
Wiring loom holder?
Wiring loom holder?
#6
Burning Brakes
I've recently run across 2 sets of these covers, bboth with model year 86 in the castings. My old flip wing '87 had the intake without the center ribs (I've seen VERY few intakes without them) but did not have the 3 holes up front in the cam covers. I'm guessing very very few early S4's had these castings. The holes in both sets I've seen were never tapped from the factory. It was a stillborn mount for something that was changed very early on. Porsche must have used the original batch of castings on the very 1st S4's.
edit: Rob, look at the other 2 spark plug clip bracket holes not being used. I bet they aren't tapped. Leads me to believe you were right about the different wire routing?
FWIW, I've also seen castings with the 3 holes cast into the ribbing, but not drilled from the outside. Perhaps another change before deleting them altogether.
edit: Rob, look at the other 2 spark plug clip bracket holes not being used. I bet they aren't tapped. Leads me to believe you were right about the different wire routing?
FWIW, I've also seen castings with the 3 holes cast into the ribbing, but not drilled from the outside. Perhaps another change before deleting them altogether.
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#8
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Totally interchangeable across all 87-95 motors. I have a set of these early covers on my stroker, which has 91GT heads. No pluses or minuses AFAIK.
#9
Thanks!
So what are the differences between the S3 covers and the S4 covers? I though I had seen a write up on that at some point, but search was no help, and I don't have a set of S3's off the engine that I can hold side by side.
So what are the differences between the S3 covers and the S4 covers? I though I had seen a write up on that at some point, but search was no help, and I don't have a set of S3's off the engine that I can hold side by side.
#10
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I've never seen the underside of an S3 cover, but here's a comparo of the exteriors:
#13
They don't look too different, but they are very different with how they attach.