ok i just got some 85mm rsmachine pistons and i want to know what size ring gap should be good for my all motor b20v

 

well first what is the end gap right now?? have you checked that? and make sure you have the ring square in the bore. take a bolt(or something fixed length with a shoulder you can butt against the deck) and go around the ring in 4 places and make sure it is square with the deck. measure gap with a feeler gauge and report back. it might be .018 or .020 or something and you will just be stuck with what it is.