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New cylinder, oversize ring gap

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I have a newly replated cylinder from Power Seal USA that was sized to the Athena #1 piston I sent them. I am using the rings that came with that piston. With the rings set about 1/2" down in the bore from the top using the piston the ring gap is >.45 to < .5mm (.017-.020"). The max gap in the manual is .4mm. I checked with a go no gauge is why the range, it's all I had with me at the time, but the point is it is larger then the max gap in the manual. I know this is only .004" over max, but I would have expected something smaller that would require me to file them to set the gap myself.

I had a #2 piston in the old cylinder and the ring gap was over spec (about the same) but the bore was at max dia. I was only measuring it with telescoping gauges but the ring gap (+ the compression test was low) is one of the reasons I got my spare cylinder replated.

Back when I put the #2 piston in the old cylinder I checked the ring gaps from rings out of new #1 and #2 Athena pistons. The ring gaps for both sets were the same so I assume they use the same rings for both piston sets. The rings from the #2 set have about 5 to 10 hours on them and still measure the same gap in the new cylinder as the new #1 set.

If all this sounds bad, I will go into check the bore dia and or looking for different rings. BTW the piston feels much tighter in the bore then it did in the old cylinder and feels like a good new fit.

I would normally have more information like bore dia. exact ring gap instead of go-no-go, etc, but I had to drop it and run out of town where I am now.

So my questions are:

Anyone have problems with new Athena rings having a larger gap them max in a new bore?

Is .45 to .50mm (.017-.020") ring gap acceptable, since the max in the manual is .4mm (.016)? Should I be worried about, at the most, .004" oversize gap?

Is that correct the the rings are the same for a #1 and #2 piston?


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