What rings do I need, weird 250.

[Rbranst]

Double D - thanks a lot - that helps. Interesting thing about my piston is it sure looks a LOT like MC pistons I see. But the bottom is machined and doesn't look like the other forged MC pistons I see on the bay.
I have been keeping an eye out for MC Ring sets, they seem to pop up often. I would need a 74 + .060" or a
Set of .090 on there right now - Actual MC Supply NOS. - Could I file these down? they would be .762 too wide. Price is right at $18.

[Rbranst]

Bottom of my piston.

Picture1.jpg

Bottom of typical MC piston

s-l1600.jpg

[Eldert]

the bottom of my MC piston looks the same as the bottom of your piston .

its machined to .

i think you need a set of 0.080 rings

[Rbranst]

Thanks for the feedback that helps a lot!

[double diamond]

MC catalog shows .003”-.005” piston clearance, .006-.008” for racing. Measure at the bottom of the piston skirt with a feeler gauge. Aldo, the bore in your cylinder wasn’t properly honed, if it was honed at all. Verify the parts are good before investing in a ring set.

[Nick]

I had Venolia make pistons for my BSA and Triumph. These are modern pistons with modern rings and they'll make them to whatever finish size, comp. ratio you want.