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- - Bottom End (http://forums.pelicanparts.com/911-engine-rebuilding-forum/302412-bottom-end.html)

Hi all,

I'm looking at a 3.2 coupe and the bottom end has been done: rods, mains, along with new valve guides and seals.

It has 130K on it and the P/C's were left alone.

Is this out of the ordinary? Why replace P/C's even with 130K if they are fine? Or is this just the cheap way out?

The owner only has 2K on it since, so it runs and looks great otherwise.

I will be looking at the full build sheet and talking with the shop(one of the best around) to discuss.

Thanks in advance for any input!

It's not uncommon for these engines to have good rings/pistons/cylinders after 130k miles. I've rebuilt 3 of these engines now and haven't had to replace the rings on any of them. The last one I built I bought new "Goetz" rings for and didn't use them because the new rings had more end clearance than the old ones. I sent them back and re used my old rings. The should have measured the clearances on the rebuild and if they were within wear limits then no need to replace them.

-Andy

Well...when you change your pants, do you put on clean underwear, or leave the old pair on? I change them, after all I have my pants off, so why not right? :)

All kidding aside, in my experience, I would have dropped in new p/c if your going through the whole block. They may measure fine, and be within wear limit....but 9 out of ten times they are near the end of that figure, and they get tired, rings lose their tension, lands get work hardened from all that mileage, and the ride will form at the top of the cyl. The cross hatch will be smoothed down, so the walls wont hold the oil as well and so on and so on. I have seen people re-use high mileage components...but to me its not worth it, theres not much life left in those parts. Besides, now the top end is fresh (Presumably) and if done properly is sealing tight, which means that you will get more oil consumption due to blow by past the tired ring package. It may run fine and be OK, but its probably going to use a little more oil at the very least. BTW RE-RINGING IS TO BE AVOIDED!!!