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Discussion Starter · #1 ·
So I had the cylinders honed, pistons blasted, and brand new factory rings. Cylinders measured well within spec on all measurements as did the pistons. When I installed the pistons with the rings they are VERY tight. So tight that with no head on I couldn't spin the clutch basket by hand. Anything I might be missing? Should I lube up the rings and walls or might this be normal. They aren't binding just tough. I checked the gaps on all rings and they are perfect.
 

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owdskl said:
So I had the cylinders honed, pistons blasted, and brand new factory rings. Cylinders measured well within spec on all measurements as did the pistons. When I installed the pistons with the rings they are VERY tight. So tight that with no head on I couldn't spin the clutch basket by hand. Anything I might be missing? Should I lube up the rings and walls or might this be normal. They aren't binding just tough. I checked the gaps on all rings and they are perfect.

Did you measure the ring end gap before fitting?
 

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owdskl said:
So I had the cylinders honed, pistons blasted, and brand new factory rings. Cylinders measured well within spec on all measurements as did the pistons. When I installed the pistons with the rings they are VERY tight. So tight that with no head on I couldn't spin the clutch basket by hand. Anything I might be missing? Should I lube up the rings and walls or might this be normal. They aren't binding just tough. I checked the gaps on all rings and they are perfect.
I'm new boy on the block so I'll have to ask what model you have and was your enging running before your work?
As I'm not a pro you'll have to wait for the master gurus to answer your question but it souds slightly worrying to me. Is is possible that your pistons has "swelled" from the blasting?

EDIT
Master guru Rod to your rescue. :D
 

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Discussion Starter · #4 ·
Measured ring end gap at .012. Don't think the pistons would have swollen from the soda blasting plus without rings the slide easily without much clearance as they should. I have done a dozen pistons and this is a first.
 

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Discussion Starter · #5 ·
Also I didn't see anything specific about a top or bottom of rings but that shouldn't matter either.
 

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I'm assuming the .012 gap measurement is in inches.... IF it's in mm, it is too small (tight)... AND, YES, there are top and bottom sides to each ring that MUST be correctly oriented.......However, it should feel tight when turning by the clutch basket.... Try spinning the crank using the alternator rotor bolt head....
 

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Discussion Starter · #7 ·
I'm going to try that next. I was still in the process of putting the motor back together and hadn't put the alternator back on. On the factory rings how are they marked. The 2 compression rings there is one that has the slight taper and silver which is on top then the all black squared one is on bottom. And yes that was in inches.
 

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No, there is a top and bottom side to EACH ring!.... The manufacturers mark must be up.... Your order is correct, but they may be in upside down.....
 

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Discussion Starter · #9 ·
I'll check that. Do you guys oil up the cylinders and rings or just the cylinders?
 

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Discussion Starter · #11 ·
I checked for the N on either side of the compression rings and there isn't one. Any thoughts?
 

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The top ring is nearly symetrical, but it does have a slight taper, and the wide side (smaller bevel) goes down.... the second compression ring is usually more obviously "ramped" at a slight angle... (its cross-sectionally trapezoidal, not rectangular or square)... The wider side should again be down towards the oil ring...... Some second compression rings have an undercut on their bottom side as well (the 350's come to mind)....
On 1-piece oil rings, I generally put the thicker "edge" down..... I don't see it mattering much on 3-piece oil rings.... JMHO......
 

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Discussion Starter · #13 ·
Thanks for the info. I'll take a look on Friday when I have time to breathe.
 
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