Oil ring (Rings)

[jpian0923]

New oil ring/rings don't fit in the bore. Shall I modify them or use the olds ones?

[ronstory]

When you say "don't fit in the bore", where is the problem? Too wide, deep, long or short?

Mine required some fiddling and sliding around to get them spaced correctly.

[Al Schober]

Is it possible you received rings meant for a .010" oversize bore? Double check your order and what was sent. Misteaks do happen.
I would NOT cut them down to fit, get the right ones.

[jpian0923]

The diameter of the oil rings (3 components make up the oil ring) is larger than the cylinder bore. The two compression rings have a gap that compresses while it’s in the cylinder, the oil ring doesn’t.

[jpian0923]

I still need help.

[Dave Neptune]

Some "sets of rings" are matched to the bore when purchased. That means the "end gap" of the rings has been set to the bore specified.

There are also sets of rings that are for a particular bore IE the curve of the ring, however they are not "gapped". The gap is a spec for the "end gap of the rings" when "you" want to set the gap. The gap you set can be either increased or decreased as desired. The "gap setting" is what the factory rings are set at from the engine supplier.

Ring gap has a lot to do with the particular engine you are working on and what you want to have that engine do. Bigger loads means a larger gap because the rings expand from the heat of the fuel IE more heat more expansion and thus more ring gap clearance.

These A-4's are for sure at the min gap end of the equation.

To set the gap you install the rings only into the bore and with feeler gages measure the gap and cut with a fine file to the desired gap. I think the desired gap spec would be in the manual. Or a chat with Ken in parts is in your future.

Where did you get the rings and what size did you order? Was the order for your bore size. Check on these.

Or you just may have the wrong rings.

Dave Neptune

[jpian0923]

I ordered them from Ken at Moyer. I gave him the piston size that’s stamped on the piston, 2.5605. Also got the sleeves from Moyer on the same order. I can’t imagine the rings not matching the sleeves.

[sastanley]

Jim, Give Ken a call and go over this with him. He will help you figure it out.