Here's my problem. The last set of Wiseco 85mm rings I bought didn't get me the ring gaps I wanted. This is on a Evo IX block that was only honed. Before the rings were filed, the top ring was .015" and the bottom was at .025-.026". The gap I was wanting was .018-.019" for the top, which I got once filed and .022-.023" for the bottom, which I couldn't get so I left the bottom rings alone.

I decided to take the block to the machine shop to eliminate any questions of the blocks condition as the reputable shop I bought it from as a "built" short block was simply assembled. I had the main bores checked and the cylinders honed to get a ptw clearance of .004"

The cylinders are now 3.348" or 85.04mm so could a 85.5mm ring set be filed down to fit or would they be out of round in the cylinder?

Thanks in advance for any advice.

 

Any ideas? Right now, the 85mm second ring untouched is leaving a gap of .030" in my cylinders.

 

0.25mm (about .010") is about as much as you should vary in specified ring size to actual bore size. If you install the larger bore rings you'll start to loose the intended shape of the ring, and add additional tension against the cylinder wall (more "preload").

You don't have many options as the rings that are included are designed for a specific bore size. As you found, the gaps will only get bigger with a larger bore. You may get lucky if you order another set and it happens to have a smaller gap to begin with, but it's not going to be much.

 

Hmm, I have a good feeling that the top rings on a new 85mm set will have the gap I'm needing without being filed. I may try my luck with a different brand of rings though.

 

call a few ring mfg's. some may be willing to burnish a set to the size you need.