Piston Ring Question

[SCBryan]

There was no first set. This is a new build. I purchased the partially completed project and this is where I am at this point.

[Bill Shields]

Ah...was someone else had a set of rings fail...sorry

Properly packed piston rings with either yard or braided packing will work well...but doing it correctly is a learned art...hence folks are leaning to one piece PTFE.

All things considered you could use o-rings alone on brass. I have done that dozens of times on water pumps.. and the rings hold up for a long long time.

Either way it is not the end of the world either way...it is not like you cannot get the pistons out and do a change.

[pat1027]

What are experiences with quad rings vs o-rings?

[Bill Shields]

I would not recommended Quads at high velocity..

[gwrdriver]

Something I've seen written about a number of times, and accounted for in TD Walshaw's ME articles on making rings, steam rings and IC rings are different animals. Steam rings exert much less pressure on the cylinder walls. I've never seen an article on modifying IC rings to better function as steam rings. Obviously we generally take what we can get and get along well enough.

When I had the opportunity I ordered steam rings from the Clupet Ring & Gauge Co. in England. Their specialty was/is steam rings of a unique design for traction engines for the steam rallying crowd but they can produce any size ring. Google will product a load of hits on Clupet, including how to make them.

[Greg_Lewis]

Something I've seen written about a number of times, and accounted for in TD Walshaw's ME articles on making rings, steam rings and IC rings are different animals. Steam rings exert much less pressure on the cylinder walls. I've never seen an article on modifying IC rings to better function as steam rings. Obviously we generally take what we can get and get along well enough.

....

Aren't IC rings very slightly tapered on the outside edge? I seem to remember that there was a right and wrong way to put them on the piston. I think that may be to help pull oil from the cylinder walls back down and help keep it from getting up into the combustion chamber. Dunno how that would affect use in a steam cylinder.

[gwrdriver]

I've only built a few engines, two early-1950s MGs and a Crosley, . . anyone remember Crosleys? I had the manuals and other information specific to rebuilding those engines so I'm almost certain if there had been any indication there was a "right" way up I'd have seen it. But those were essentially pre-War technology engines so tapered rings may very well have become standard for post-War engines.

[Bill Shields]

Many ic rings have a dot on one side to indicate "this side up". Especially with oil rings that are designed to push oil down rather than push up.

[rkcarguy]

I would not recommended Quads at high velocity..

I've printed out extensive information regarding feet per minute, temperatures, expansion/temp relation, and the like. This is correct, I think the feet per minute in a steamer exceeds the specs for the quad type rings. Glass filled PTFE seems to be the best I can find. There are hydraulic components that utilize these, as well as rings made from it that are molded with built in overlap/expansion, but you would need to buy them first and then build your pistons and cylinders around them. In my opinion, bronze cylinders, stainless pistons, glass filled PTFE rings =best it's going to get.

[BClemens]

I've only built a few engines, two early-1950s MGs and a Crosley, . . anyone remember Crosleys? I had the manuals and other information specific to rebuilding those engines so I'm almost certain if there had been any indication there was a "right" way up I'd have seen it. But those were essentially pre-War technology engines so tapered rings may very well have become standard for post-War engines.

Yep, I remember Crosley and a spinoff with their overhead cam engine used on the Bearcat Marine Outboard motor (Boston Whaler). I had a Bearcat 55 that was more like 100 HP on a 16' Dilks Ski-barge. The engine was of course mounted vertically and modified to a dry sump. Quite an engine!
BClemens

[prlawiii]

What is the source for glass filled PTFE rings?

[Bill Shields]

bar stock...turn them yourself