Ring end gap
#1
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Supertech pistons, first overbore, 9.5:1, going to run ~15+ psi boost. Supertech says .021 top, .023 bottom compression rings. Do I run this, or run them closer? They are tight now, so I have lots of options. I will probably cross-post this on m.net if nothing shows up here.
#2
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Supertech pistons, first overbore, 9.5:1, going to run ~15+ psi boost. Supertech says .021 top, .023 bottom compression rings. Do I run this, or run them closer? They are tight now, so I have lots of options. I will probably cross-post this on m.net if nothing shows up here.
#4
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Do NOT run tight ring gaps on a forced induction or nitrous motor! The rings expand under load and can actually butt ends and cause ring/land failure. Rule of thumb on blown motors is .006" end gap per inch of bore diameter on the top ring and .005" on the second ring. This equates to .020 on the top and .017 on the second. If Supertech is suggesting .021 top and .023 bottom for your pistons in a turbo application, do not run any less end gap. Use a piston ring filing tool carefully, and check clearance by putting the ring in the bore and squaring it with the head of a piston. Each ring needs to be filed for a specific bore and kept organized so it gets installed in that bore. Use a small file to deburr the ends of the rings after you have them file fit to the proper clearances.
I bought an engine builder for this.
#6
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You should have gotten a sheet with your pistons that says what endgaps to run based on your intended use. If you don't have it, call Supertech and they'll email it to you. It's a multiplier based on street/roadcourse/drag/nitrous/etc use.
#12
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Just follow the sizing chart they give you with the pistons. I did my wisecos at .017 for the top ring and .019 for the bottom ring. Oil rings didnt need any sizing. For example i did the .060 overbore on my 1.6, the bore size is 3.1299, follow the chart for the proper application (street moderate turbo/nitrous) .0055 x 3.1299 = .017ish(top ring) and .0060 x 3.1299 = .019ish(bottom ring). Just follow manufacturers specs, figure they've been making pistons for longer then ive been alive so they must know best. Be careful gapping too big as well, you'll have a smoke'mobile.
#14
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Well this is serendipitous, I was just about to post the exact same thread.
I bought the NPR rings from eGay and found they had about a .012-.014" end gap which was slightly larger than the old rings I pulled from y8s old pistons. I was about to kick off at the seller.
My engine is only NA but will still be making a bit more power than stock so is .012-.014" ok? My overhaul manual states between .006" and .009" as standard and a maximum (your engine is shot if you get to this point) of .036".
I bought the NPR rings from eGay and found they had about a .012-.014" end gap which was slightly larger than the old rings I pulled from y8s old pistons. I was about to kick off at the seller.
My engine is only NA but will still be making a bit more power than stock so is .012-.014" ok? My overhaul manual states between .006" and .009" as standard and a maximum (your engine is shot if you get to this point) of .036".
#20
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Do NOT run tight ring gaps on a forced induction or nitrous motor! The rings expand under load and can actually butt ends and cause ring/land failure. Rule of thumb on blown motors is .006" end gap per inch of bore diameter on the top ring and .005" on the second ring. This equates to .020 on the top and .017 on the second. If Supertech is suggesting .021 top and .023 bottom for your pistons in a turbo application, do not run any less end gap. Use a piston ring filing tool carefully, and check clearance by putting the ring in the bore and squaring it with the head of a piston. Each ring needs to be filed for a specific bore and kept organized so it gets installed in that bore. Use a small file to deburr the ends of the rings after you have them file fit to the proper clearances.
On stock pistons and and stock bottom block on a 1.6 I'm running 8-10 psi on a turbocharger what gap measurement should I have for top and bottom