Franks928s

I recently purschased a 87 S4 that I knew at the time would be a project car. I already own a 85S that's pristine so I thought this would be my project for the next year. Before I dump a lot of money into the exterior/interior I wanted to address the engine. Little did I know prior to purchase about the challenges with automatics, torque tube clamps and thrust bearings. Therefore, I had mine checked. The results are Crankshaft end play measured at 4.06mm (spec is 0.4mm).

Its been suggested to me to have the oil pan dropped and someone check for any visible engine damage. (also a costly exercise). My questions: If there is not any visible damage to the block or bearing, am I ok with being this far out of spec if I use a superclamp? OR, should I run fast from this car?

SeanR

The CRANK moved 4.06mm? That's a lot.

Now if it was the flex plate moving that much, I'd not worry.

Lizard928

I think that you need to get a dial indicator and inspect this yourself as I think that it is probably just the flexplate moving back that far.

if the crank moved that far it would not run once hot.

blown 87

We are in one right now that had .018" inch end play and it was almost through the copper, there was no babbit left.

You either have a bad reading or a junk motor.

Mongo

It sounds like that measurement maybe the distance the pinch collar moved back. Did you release the pinch collar bolt and then do these measurements from the collar and spline distances?

Black Sea RD

I believe it was also suggested for you to contact your mechanic, verify the readings and if correct, discuss the need for a visual check of the engine internals before doing anything else.

Good luck!

Mrmerlin

if you had that much play in the crank then pulling the dipstick and with a piece of lamp cord ( the reason to use lamp cord is because the dipstick will also create some metal flakes when its inserted into the dipstick tube and give a false readings )
take an oil sample drip the oil onto a black piece of cardboard go into the sun and look at the oil if you see lots of metallic flakes then you know you have major problems with the thrust bearing. IF OTOH you dont see any flakes then you need to reinspect the crank end play .004in. is new and .016 is max but to be safe it should be no more than .012in. . This is done with the flex plate clamp loose

Franks928s

Thanks folks for the quick responses. I have sent a note to my mechanic for clarification of the what/how was measured and should know tomorrow. He's got a great reputation here in Charlotte and he's a master Porsche mechanic who also does a lot of work on the racing circuit.

I'll post his response once I receive it. My concern is am I "ok" if there is NO engine damage and my specs are still out of line with Porsche specs? I have a number of bids out currently for painting, new interior and planned to do the norm stuff like timing belt/water pump, Tuneup and hoses. As you guys know, CHA-Ching$! Hence my wanting to be smart with this one. I guess we need to wait until I hear what was really measured.

Merlin - thanks for the test tip. I'll personally try that over the weekend when I visit the garage.

Frank

GregBBRD

I've seen them with way more than an 1/8" end play....so much that it isn't worth the time to put a dial indicator on them.

4mm= .157"...just more than 1/8".

blown 87

That might be a bit much Greg.

I can not understand how some one can drive one that long with out thinking there may be a problem.

BTW, John said the parts will ship Monday, long story........

Franks928s

Greg - are you saying that those cars were "ok" or would you classify them to be on a "death march?"

What's still confusing to me is say there is excessive play but the engine lucks out and is not damaged. What' then? Does something like the superclamp just stop it from getting worse or, are there other remedies that should be considered? (and cost effective)

soontobered84

Sorry, but there is going to be nothing "cost effective" about excessive crank end play. That said, maybe it's .004"!

Bill Ball

Isn't the thrust bearing face only 2mm thick? With 4mm of endplay, if true, there should be huge chunks of engine block in the oil.

BPG_Austin

I just did this (new mains/rods). If they're out of spec don't bother trying to find a mechanic to fix it. IMO would be cost prohibitive.. I'd find a used engine to throw in if you're stuck with the car. Otherwise just find another example to restore. A pic of my thrust bearing. .019". It probalby could have run for a long time with a superclamp since there was plenty of meat left on the thrust surface. But, if Greg pulled one with .018 and it was trash, once you're out of spec you're not safe.

Hopefully you have a clarification issue with your mechanic.

blown 87

That one is toast, no babbit left.