Soft piston ring?

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nrpetersen

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nrpetersen
Has anyone ever seen a piston ring that has been so overheated that it can be twisted into an "S" shaped pretzel? I thought the base metal was cast iron.

Continental A-65 chrome top ring with the gap obviously upwards.
 
nrpetersen said:
Has anyone ever seen a piston ring that has been so overheated that it can be twisted into an "S" shaped pretzel? I thought the base metal was cast iron.

Continental A-65 chrome top ring with the gap obviously upwards.
Click to expand...

Steel cylinder will have chrome rings, chrome cylinders will have iron rings. If you can twist your ring 180° into an S, it's ****ed.:lol:
 
I think a picture is needed. No way I can see that happening unless the piston or the bore is seriously horked.
 
I've seen some seriously overheated rings that would bend like solder. The pistons looked like hell and so did the cylinders. Not a common thing however from what I've seen.

Frank
 
this is what happens when you run them hard they over heat the rings and they collapse into the ring groove and never seat. many mistake this as a glazed cylinder.

Proper test cell runs prevent this.
 
nrpetersen said:
Has anyone ever seen a piston ring that has been so overheated that it can be twisted into an "S" shaped pretzel? I thought the base metal was cast iron.

Continental A-65 chrome top ring with the gap obviously upwards.
Click to expand...

probably some one flew it around with high power, and slow flight. now watch for a cracking cylinder, it was never meant to be that hot.
 
Gray cast iron cannot be annealed. It's just brittle because it has so much carbon in it. Cast rings don't get heat-treated during manufacture. Any heat that could damage a cast ring would melt the aluminum piston long before the ring would suffer. I have welded plenty of gray cast in my time and have never, ever seen it get soft and bendable.

Might be ductile (nodular) iron rings. They'll bend.
 
Dan Thomas said:
Gray cast iron cannot be annealed. It's just brittle because it has so much carbon in it. Cast rings don't get heat-treated during manufacture. Any heat that could damage a cast ring would melt the aluminum piston long before the ring would suffer. I have welded plenty of gray cast in my time and have never, ever seen it get soft and bendable.

Might be ductile (nodular) iron rings. They'll bend.
Click to expand...
That's probably what it is. I can't conveniently get a picture but a friend showed me the ring from his T-Craft where the cylinder was simply deglazed and a new ring set installed (don't know about pistons). The ring was plastically deformed such that it looked like a letter "S" and would almost lay flat once again! It was obviously chromed and the OD surface was slightly corroded opposite what was the gap. He saw the engine disassembled but made no comments on other internal trauma.

Weird. (Gonna try get a PIX)
 
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Improper leaning can cause cylinder overheating.....which ruins the ring heat treat.....once the rings become soft wear accelerates.
 
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