So my built motor spun a rod bearing at the end of August and I’m finally starting to put everything back together.

While I had everything apart, I had the machine shop do a cylinder hone and check the bores and pistons for roundness just to be safe. I was told the pistons were all reusable.

Today however. I got around to starting the bottom end assembly and found a piece of bearing material embedded in piston #2 (the same cylinder the rod bearing spun on). The embedded flake is completely smooth and doesn’t even catch a fingernail. All of the cylinder walls had minor scoring when torn apart but cylinder 2 wasn’t any worse than the rest.

I’m looking for a second opinion. Should I replace this piston? Try to remove or file down the bearing material? Toss it in and forget about it? Haven’t been in this situation before so any insight is appreciated.




As always, thanks in advance.

-Zak

 

I would scrape it out with a sharp knife and dress the surface lightly with a fine single cut file or stone. Just make sure nothing is protruding pass the skirts surface.

 

I ended up trying to scrape/pick it out with a box cutter blade then a really sharp pocket screwdriver. Couldn’t get it to budge and couldn’t seem to get under it at all. I ended up using a fine file to take a bit more material off of it (it was already flush with the piston) and installed it. Am I exceedingly stupid to think that it won’t be an issue if it’s a few thousandths below the piston surface?

 

I think it will be fine.

 

Killer. Thanks for the input as always, Leo.