Re: "Honing rings"

[PM T2]

Must admit that I’ve never heard of nor thought about sanding the outside diameter of piston rings. I have lapped the flat surfaces of old rings that I was going to use again, but don’t make it a habit to go after the OD. Can’t imagine that sanding the rings helped as much as you think.

One of the reasons rings start to leak compression is they wear and have thinner cross-sections in critical area, and sanding them is only going to remove more metal. That’s just one reason for lower compression, of course there are many others.

Deglazing the cylinder walls probably helped more than you give it credit for. Removing carbon buildup on the ID of the rings (and grooves) and making sure they move freely in the grooves would be more important (in my tiny little mind at least) than scuffing the OD.

Jay Walls has learned a lot about piston rings and getting them to seat better after honing the cylinder(s), so he’d probably be a better guy to discuss it than I.

FWIW the "ribs" on the OD of the rings are machining marks from being turned in a lathe, which is how most piston rings are made.

and in another "FWIW" Harry Brinkman used to always recommend replacing only the top ring on a piston, he just thought that it didn’t make much sense to replace all of them when the top ring does most of the compression work anyway. Plus, with some of our old motors, ring supplies are getting smaller in certain sizes, so it helps stretch out the supply, and saves a person a few dollars as well. Just a thought.

Hope it helps.

Best,
PM T2

He's livin' in his own private Idaho..... I hope to go out quietly in my sleep, like my grand-dad did..... and not screaming, like the passengers in his car...