ok. this is good. keep the input coming. Yes the .5mm increments are important, I can't tell you enough about the quality of the XXrings versus the iron rings available currently. The RA surface finish is about 3-4 versus the 20 ra commonly seen on iron rings. They are very round and very flat...just superior sealing all the way around. Doing .100 over with the same set of rings is possible, but oil ring tension goes well higher than necessary. .002" per side isn't going to make a difference on cylinder wall strength, so we'll go .104 over. We'll also come out with a .084 over likely based on the input of a few of you above.

These XX rings will always be available. We sell these rings to many of the other piston companies and Total Seal.-they are the standard we all use for sport compact.

One other bonus is we've had a new forging become available that has a better fit to this bore size. The pistons we're doing for Rob are 45g lighter with the same crown thickness even at .100 over than our +045's. We will switch the forging over for all the sizes and we'll loose loose 55-65g on the .025's and .045's.

Thanks all for your help. I'll let this thread go for another week to get more input before I pull the trigger. From there, we can expect new parts on the shelf in about 6 weeks.

Rob, I'll discount your customs to stocking piston priced so you're not out in the cold on this one and I appreciate your efforts to promote us. Right now, every set we send out keeps our guys running the machines here in Ohio.

Hi there, sorry for the delay. Things have been NUTS! I’m interested in gettings some .080 and .100 oversizes added (in whatever closest mm).

-6.3cc is the actual volume of the pistons. We went symmetrical valve pockets to lower price and the volume went up a bit from the original design. That might be able to be changed to a lesser depth---they’re extremely deep now. Any thoughts?