When To Rebuild Bottom
 

Bought my '86 951 in summer 1996 with 89K on clock. Shortly thereafter, I added a MAF, K27DR turbo, fuel pressure, special head, and intake with all new valves. The car goes to track about 6-7 times a year and now has 130K on its odometer. It runs well and makes no strange noises. I change oil/filter every other track event and use Mobil 1. It gets run hard but rpm's are kept to six grand or less. I don't abuse it.

When should I replace bearings?

Next time you take your filter off cut it open. If you find a bunch of brass filings in there, then it's the bearings. A little is normal, but a bunch is bad. You should then consider replacement.

As a general rule a track driven 944 Turbo should get its rod bearings replaced every two to three seasons. Figuring a season to be 10-12 track events at approx. 2 days per event and 90 minutes per day that's about 5000-6000 track miles. The main bearings are very stout and should last longer than just about everything else in the engine.

If you aren't pushing the car to its absolute limit engine wise then 10-12,000 track miles may be a possibility. I'd change them sooner as a precaution. Up to know I would say you have been lucky.

BTW changing the oil every 2-3 track days is reccomended due to fuel dilution of the oil. This occurs only at the track and can be easily smelled on the diptstick.

I have a leaking pan gasket that will be getting replaced this winter. I probably will also replace the pan with one that is supposed to lower chances of oil starvation.

Anyway, while I have the pan off, can the rod bearings be replaced without removing the pistons? I'm thinking you can just turn the engine over to make them accessible for rod bearing replacement......Right or wrong? I have never done this before.

Yes you can. No need to remove the pistons at all.

Thanks to all for the information. Just two more track events this year - Road Atlanta and Charlotte (Lowes) and I'm home free....

The procedure is pretty well documented in these...

http://www.tech-session.com/Paragon/Tech/944_rod_bearing_replacement.htm

http://members.rennlist.com/9201toolclub/rodbear.htm

OK, so now I have begun sniffing dipsticks. My wife is wondering about me for sure now.

Seriously though, the car has two track meets on its oil. I sniffed it last night. It did not smell like gasoline at all. It smelled just like the dipsticks in other cars of mine. They all have an odor but not a gasoline odor.

Am I supposed to smell gasoline in it? It is just slightly darkened. This spring I cut open an oil filter and found nothing except the filter element. The magnetic drain plug only has a slight coating on it. Can't find any metal pieces.

Thanks to all for info on bottom rebuild and other guidance.

[This message has been edited by Lawrence Coppari (edited 10-19-2001).]