924Board.org

[Chrenan]

Hey Brock, just caught up on this thread. That was a crappy Sunday, loading your car onto the trailer was depressing, I felt so bad for you.

Some random thoughts:

Justin's 951 is an 89, Russ's/Bob's 944S2 is a 90. Both have the late style factory plastic baffling insert in the oil pan. When I first got my '87 951 and dropped the pan updating to the late style baffling was top of my list. I've never seen an oil light flicker on the runways or at Stratotech. I'm very carefull to keep the oil at the top line, but not above (froth).

When you installed your oil pickup, did you remember to put the metal tab between the pickup and the block and bend the tabs over the bolt heads?

Justin has an accusump setup in his 944/968 engined race car if you want to look at the layout, I was there lending a hand bolting it in last night. Honestly, I don't think you need it for the events we run locally if you are on street tires, but I will defer to the more knowledgeable 2.0 engine mechanics here of course. If it really was oil starvation at the pickup I would think baffling and scraper would be enough. However, like Cedric says, he doesn't have issues on R-compounds. You never saw the oil light with the old engine, so I'm not sure what happened.

Honestly, the more I think about it, my money is on machine shop error. It was a trusted shop, but it is now closed and your stuff might have been there during a period of workplace stress with less attention and care given.

I always ran 20w50 in my 924, on the old engine and the one I rebuilt. I run 20w50 in the 951 as well. I don't think its that, even a rebuilt 924 doesn't have tight tolerances compared to new engines. Time will tell, the oil will give you a clue when it comes out, or the fliter when its cut up.
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1987 951 - M193 Version for Japan

[Carrera RSR]

This is what I found in 8000 mile since rebuild engine I bought. We dyno'd it in the donor car, all good. I dyno'd it in my car, all good. First drive up the highway and 20 miles in it starting knocking whilst holding a set rpm. No knocking on acceleration or deceleration. No knocking on tick over. Damage done within 5 miles of a noticeable knock.

No.4 big end bearing hammered to death. Did not spin but clearly some oil starvation caused initial wear before journal was completely hammered shut



Crank and rod are now scrap and a full bottom end rebuild needs to be done again! Three turbo engines and all require different areas of rebuild!! Hopefully I can make one good one out of three or new pistons and rods will be needed. I am planning on the latter.
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

[Martijnus]

So if the light went on, you should have seen it coming at the pressure gauge.

I don't think you're looking at a pressure gauge in the situation you mentioned but I am interested in the pressure you've read during several situations.

I've seen engines that had worn bearings after a rebuild, and I found a leaky gasket at the pickup tube. That means you suck in air which is not good for oil pressure.

That, combined with the turing/braking situation could be the death blow.

Since you say you didn't have any problems in the same situation before rebuild I wouldn't blame it on coincidence.

Anyway... if the engine is opened, keep that in mind when you pull the pickup off. If you're careful and lucky you can easily see if it didn't seal properly.

Could just be bad luck though. Sucks in any case, I know the feeling when a rebuilt engine dies. In my case it was my bike's engine and the cause was a clogged filter thingy in my oiltank (which is in the frame so overlooked at rebuild)
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"Rule: Turbo's make torque, and torque makes fun." (C. Bell)

924 "50-jahre", 1981.
MSII/extra, LPG, ITB's, 5lug.
To be turbo'ed in a while.
Killed her at the Nurburgring, Porscheless at the moment

[Brockoli]

The oil dipstick is the right length (the end stop hasnt moved), so I was measuring the proper oil levels.

I definitely bent the tabs over the oil sump pickup bolts, but I dont remember if I installed a gasket.... I will find out when I open it.

Cut open the filters and didnt find much inside the intial start up filter (very small amounts of copper looking particles). The last filter had about 100kms on it and was filled with big, small chunks and glitter.


Here are the pics of the oil and filter...








Mahle oil filter insides



Mahle vs Bosch insides (Bosch closest filter material, Mahle furthest away)

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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)

[Brockoli]

Looks like I spun #2 connecting rod bearing The mains look ok, and #1 connecting rod bearing looks like it got pretty hot too. I will post pics when I have time.

During the rebuild, the gasket kit I had did not have the oil sump pickup gasket. I did however use form-a-gasket sealer on the oil pickup to block surfaces.

I believe oil starvation issues for the #2 connecting rod bearing is fairly common with 944's and there are aftermarket fixes for this problem, i.e. lyndsey racing baffle door/oil pickup collar. I plan on doing something similar with my next build.

I think with the tighter left corner and the high rpm I was running in this corner on this years auto-x track contributed to the problem. Still haven't (or maybe will not ever) confirmed if it was a assembly, manufacturer, machining error. The use of gasket sealer instead of a fiber gasket couldnt of helped the issue.

So know its down to what needs to be replaced. My crank is scratched where the con rod bearing spun. So I need new con rod bearings, and I have spare con rods to replace the damaged one(s).

Does anyone have second oversized con rod bearings? If they are available maybe I can get the con rod journals shaved and reuse the crank (with new main bearings). I did balance everything so this would cut down on balancing a new crank. Any other ideas other than replacing everything....let me know.
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'80 924 M471,Wideband O2, Full coilover susp,23/19 sways,Bilstiens,KLA Strut Brace,Roll Bar,Test Pipe,BBS RS, Willwood BBK

25% of a '87 944 Chumpcar http://straightpipe.ca/forums/showthread.php?t=2454

'79 924 Sebring Edition(Sitting)