Replacing just 1 95mm piston?
 

Hi engine building boffins :D

I have a set of good 95mm 3.2 P&C's (9.5:1 C/R) with 80k miles on them, however, one of the pistons has a cracked ring land :(

Is it possible to replace just that one piston with another used piston?

What do I need in order to ensure the replacement piston will suit/match that cylinder? Is there a specific code/marking I can refer to on the barrel so I can ask the wreckers for a suitable match?

It's either that, or I can have them bored out to 98mm, Nikasil plated and order a new set of JE's to match.

Any ideas/suggestions?

What did it crack from detonation, or have you had the pistons reringed? If you replace one, what condition do you think the others are in? If it was from detonation, what about the rod bearings, the main bearings, the wirst pin bushings? All things that you should consider instead of just throwing another piston in.

Did you crack the ring land with your turbo?

If so, I like this option:

and get compression between 7.5 and 8.5:1 depending on your goals.

And who are you calling a boffin !!?@>? Just kidding.

If you decide to go with a single used, I would make sure to get it balanced to ensure that it's in spec with the other pistons.

Based on all of the reading I have been doing here I understand that it is wise to replace the piston for a used piston & cylinder. It had always been mentioned here that when removing pistons and cylinders that the sets of pistons should be kept with thier perspective cylinders ie: replacing with a used matched set of piston and cylinder. I do know that the Mahle cylinders are stamped on the side with designations for size & weight and that inside bottom of the piston is numbered. Hope this helps but please verify with a more knowledgable person. I found a wealth of information on this site by entering in a search for (replacing cylinders) or (cylinder specification). Good luck! Johnny O

Thanks guys. I think I'll replace the whole P&C, instead of just the piston. Will check out the markings on the cylinder to ensure I find a replacement unit.

Cheers!