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Discussion Starter #1
Anyone got any getter ways to stagger piston ring end gaps and keep them from realining. I have 300 miles on a rebored motor and have found that most of my compression and oil ring gaps are now in line with each other. I did very carefully stagger the ring end gaps like Ford recomends. The compression rings faced towards the front of the engine 1 1/4 inches above and below the pin bore and the oil rings facing towards the rear 1 1/4 inches above and below the pin bore.

Blue Fastback
 

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If someone has a way I would love to hear it. Every motor I have tore down has had the gaps lined up. From my race motors to my street motors, it never mattered, they all end with the gaps aligned.
 

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Also ... Assuming you have the correct gap in the rings to begin with ... Once the engine is up to operating temp, that gap is pretty darn small ... Not half an inch like it is with the piston sitting on the work bench
 

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Unless you have special rings, and pistons, the rings will rotate around in their lands, you cant help it. 2 stroke engines have a pin in the land, and special rings so they dont rotate. Maybe there is some like that made for 4 stroke, I dunno for sure.
 

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Discussion Starter #7
I thought about using gappless rings but that still leaves the oil rings to realign themselves. It is just kind of disapointing to see ring gaps realigned after such a short time. I thought maybe someone had a better way to stagger the rings. I just got an email back from a piston ring engineer who said that movement of the piston rings is due to thermal distortion. He said when the engine heats up the ring gaps finds its way to the most distorted part of the bore. The reason I found out about the ring gap issue comes from a problem I posted about 2 months ago. I had a strange rattle noise I had that could not be identified. The motor is now all torn down.


Blue Fastback
 

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The rings are supposed to rotate, otherwise the small ring end gap would wear a spot in the cylinder wall. Rotating rings wear the cylinder bore evenly (at least thats the idea) The reason they rotate is due to the cross hatching of the bore, as the piston moves up and down it makes the ring rotate. Also the design of the ring itself promotes rotation (how the ring "twists" in the piston groove as it goes up and down). I don't think it's possible to prevent the ring gaps from lining up sooner or later, but they shouldn't stay that way. Unless of course, you use gapless rings.

Just my $.02
 
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