347 ci piston ring gap??? nitrous motors
08-24-2006, 04:13 PM
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347 ci piston ring gap??? nitrous motors I'm finally starting to re-build my motor. My question is what does or has everyone filed their piston ring gaps for their nitrous engines?
My info was
.007" x bore for the top ring
.008" x bore for the second ring
top ring
second ring
oil ring
The info I got told me minimum of .015" on the oil rings. the wave ring right now has ZERO clearance. Does that Wave ring need that .015"? The rings that go above and below the wave ring have the spec'd .015" clearance.
Thanks
JEFF
My info was
.007" x bore for the top ring
.008" x bore for the second ring
top ring
second ring
oil ring
The info I got told me minimum of .015" on the oil rings. the wave ring right now has ZERO clearance. Does that Wave ring need that .015"? The rings that go above and below the wave ring have the spec'd .015" clearance.
Thanks
JEFF
08-24-2006, 08:49 PM
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What kind of rings are they? My Childs and Albert Dura-Moly rings came with a sheet on recommend end gaps for different uses.
The recommend end gap was .0045 per inch of diameter bore for nitrous use on the top ring (that was the MINIMUM recommend gap, so Im guessing for a really big shot of nitrous 500+ you should go bigger?). I cant remember what the second ring was. The wavy one should not need to be gapped but you should double check with the manufacturer. The other two oil control rings (3rd groove) should have a minimum and maximum gap supplied by the manufacturer that must be checked with a feeler gauge.
Best thing to do would be to call the company that makes your rings and see what they recommend. Measure twice, file once. then measure again.
The recommend end gap was .0045 per inch of diameter bore for nitrous use on the top ring (that was the MINIMUM recommend gap, so Im guessing for a really big shot of nitrous 500+ you should go bigger?). I cant remember what the second ring was. The wavy one should not need to be gapped but you should double check with the manufacturer. The other two oil control rings (3rd groove) should have a minimum and maximum gap supplied by the manufacturer that must be checked with a feeler gauge.
Best thing to do would be to call the company that makes your rings and see what they recommend. Measure twice, file once. then measure again.
08-24-2006, 09:18 PM
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Don't worry about the oil ring as long as the scrapers are at recommened.I believe on my old 346 nos motor i was at .26 top .28 on the lower.Your better a little bigger when it comes to nitrous.
08-24-2006, 09:26 PM
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I'm finally starting to re-build my motor. My question is what does or has everyone filed their piston ring gaps for their nitrous engines?
My info was
.007" x bore for the top ring
.008" x bore for the second ring
Thats .27 on the top and .31 on the second.
My info was
.007" x bore for the top ring
.008" x bore for the second ring
Thats .27 on the top and .31 on the second.
08-24-2006, 09:36 PM
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Originally Posted by tuff
I'm finally starting to re-build my motor. My question is what does or has everyone filed their piston ring gaps for their nitrous engines?
My info was
.007" x bore for the top ring
.008" x bore for the second ring
Thats .27 on the top and .31 on the second.
My info was
.007" x bore for the top ring
.008" x bore for the second ring
Thats .27 on the top and .31 on the second.
the .027" and .031" is what I'm set at now. I spray 150 before, now planning on more. Just lookin' for someone to back up my thoughts
first LS1 buildJEFF
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08-24-2006, 09:50 PM
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Id go .28 .30.I like just having a .02 spread between the two rings.Your better a little more loose on the end gap if you plain on spraying a big dose.Last thing you want is to have them to tight on the bottle.
08-25-2006, 05:35 PM
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i just filed mine last night.
347 with je 3.905 pistons and total seal gapless top ring
the rings were supposed to come pre gapped and the machine shop guy said just throw them in and don't worry about it. the seconds showed close at .024 on every cyl so i left them alone. the tops were way tight at .023 instead of the suggested .031.
i filed the tops to .031
i plan on using a 200 shot as well.
sounds like were gonna have the same setup, which cam you going to use?
i can't decide. it's a DD and i want my g/f to be able to drive it so i can't go with a huge lope :-/
347 with je 3.905 pistons and total seal gapless top ring
the rings were supposed to come pre gapped and the machine shop guy said just throw them in and don't worry about it. the seconds showed close at .024 on every cyl so i left them alone. the tops were way tight at .023 instead of the suggested .031.
i filed the tops to .031
i plan on using a 200 shot as well.
sounds like were gonna have the same setup, which cam you going to use?
i can't decide. it's a DD and i want my g/f to be able to drive it so i can't go with a huge lope :-/
