teazer said:The idea is to set the rings so that the end gaps don't line up. If/when they do there's a some leakage past the rings. As PJ mentioned, rings rotate in use. I want to say it's around 7rpm but I don't recall where I read that.
crazypj said:cross hatch isn't an explanation when motor is bedded in, cross hatch has gone.and cylinder is completely shiny.