Piston Ring End Gap - Part II

[Mark H.]

My ring grinder arrived from Summit yesterday. One question about setting the gap on the oil control ring. Am I correct that with a three-piece ring, only the top and bottom "rails" need to be set, and you leave the expansion ring (in the middle) alone?

Thanks.

[Mike M.]

Re: Piston Ring End Gap - Part II

you got it right, mark. mike

[Clem Z.]

Re: Piston Ring End Gap - Part II

very seldom does the oil ring rails need gapped. also when doing the moly filled compression rings make sure you do not have the wheel turning so the pressure is pushing outward on the moly insert because it can cause it to chip out of the ring.

[Mark H.]

Re: Piston Ring End Gap - Part II

OK, sorry to be such a dunce, but how do you ensure that the ends are ground square? Obviously, you hold the ring flat against the base of the grinder. Do you put the gap end over the stops on the grinder, so you pull the ring back against the stops, and then use your third hand to compress the ring so both ends are ground at the same time, relying on the pressure to keep them square to the wheel? Or is there some other trick? In investigating tonight there seems to be ample opportunity to wind up with a ring ground wider on the inside than the outside (which is what I did freehand to begin with). I must be missing something.

[Clem Z.]

Re: Piston Ring End Gap - Part II

i only grind one side and keep the edge square to the cutting wheel