ORIGINAL: earlwb
I don't know if anyone tried to make or run a .60 size engine with a mehanite piston in it.
The early Enya 60/63 prior to the 60-II in 1965 had cast iron pistons.
But just to throw in another odd-ball Russian engine, the photo is my rear exhaust version of the Stas's 42 (I also have the SE version). Plain bearing and cast iron piston with the tightest pinch I've ever felt in anything. An hour of slobbery rich running and I was finally able to hand start it
. Obviously it didn't have the advantage of a brass liner expanding so for about the first 40 minutes the piston would lock into TDC every time it stopped.