stock piston ring end gap
#1
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Car: 1989 Base Firebird
Engine: fuel injected 2.8L V6
Transmission: T-5
stock piston ring end gap
Doing a rebuild of my 350 and just bought the "Sealed power Performance Piston Ring Set" (part#SLP-E-251K) to go onto my stock pistons (1975 4 bolt). just wondering on where about my end gap should be because I don't have a piston manufacture spec to go off of
#2
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: stock piston ring end gap
.0045" per bore inch on the top ring, .005" on the 2nd, "enough" on the oil ring that it doesn't butt up against itself when it gets hot.
So, for a 350 (4.000" bore), that's around .018" on the top, .020" on the 2nd, maybe .025" on the oil ring rails. Err on the side of a bit more gap (say, a .001" or 2) rather than ANY less. Too much ring gap is a minor annoyance, even ALOT too much; too little, even .0005" too little, is CATASTROPHE and DISASTER.
The pistons are ABSOLUTE GARBAGE. Sorry to hear that you're going to actually spend money to re-use such ... ,,, ... , ... words have failed me.
So, for a 350 (4.000" bore), that's around .018" on the top, .020" on the 2nd, maybe .025" on the oil ring rails. Err on the side of a bit more gap (say, a .001" or 2) rather than ANY less. Too much ring gap is a minor annoyance, even ALOT too much; too little, even .0005" too little, is CATASTROPHE and DISASTER.
The pistons are ABSOLUTE GARBAGE. Sorry to hear that you're going to actually spend money to re-use such ... ,,, ... , ... words have failed me.
The following 2 users liked this post by sofakingdom:
NoEmissions84TA (05-20-2023), T.L. (05-19-2023)
#3
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Re: stock piston ring end gap
Good info on the ring gaps but the piston comments might be a little harsh. Those run about forever without problems, were on the engine as balanced (as much as the factory balanced back then), and if buying new pistons might as well rebore, and have to replace on rods. Machine work is crazy expensive these days. Unless really adding some power I'd not worry about reusing those slugs.
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Car: 1983 G20 Chevy
Engine: 305 TPI
Transmission: 4L60
Axle/Gears: 14 bolt with 3.07 gears
Re: stock piston ring end gap
Good info on the ring gaps but the piston comments might be a little harsh. Those run about forever without problems, were on the engine as balanced (as much as the factory balanced back then), and if buying new pistons might as well rebore, and have to replace on rods. Machine work is crazy expensive these days. Unless really adding some power I'd not worry about reusing those slugs.
Last edited by Fast355; 05-20-2023 at 11:52 PM.
#5
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Car: 1989 Base Firebird
Engine: fuel injected 2.8L V6
Transmission: T-5
Re: stock piston ring end gap
its by no means a high performance engine. just something to get the car up and running with a simple cam, carb, and headers.
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