When if ever can rings be reused?
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Race Director
Joined: Nov 2018
Posts: 13,278
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When if ever can rings be reused?
My '80 came with a ZZ4 and a Weiand 142. I've read that one of the considerations/concerns with a power-boosted motor is ring gap, that extra heat can cause them to over-expand, bind and break a piston.
It's run good so far, I don't flog it a lot, but I'm a bit leery about those rings. Yeah, I know - not the only thing to be concerned with regarding this particular engine with a blower on it but I'd like to eliminate that one concern that seems relatively simple to do. I'm sure they're at whatever gap they came from Chevy with. If I pull the pistons to file the rings, can the rings be reused? Seems I heard somewhere that once a piston leaves the cylinder you have to get new rings, then of course the cylinders need to be ridge-reamed and honed. Is this correct about rings? The engine doesn't have a lot of miles on it, probably under 5000 miles, I'm guessing not enough to warrant re-boring and going to bigger pistons.
Also, any recommendations for a target gap for the various rings? Or do you have any experience or opinions on whether this particular blower makes enough extra power for ring gap to be a concern?
Thanks!
It's run good so far, I don't flog it a lot, but I'm a bit leery about those rings. Yeah, I know - not the only thing to be concerned with regarding this particular engine with a blower on it but I'd like to eliminate that one concern that seems relatively simple to do. I'm sure they're at whatever gap they came from Chevy with. If I pull the pistons to file the rings, can the rings be reused? Seems I heard somewhere that once a piston leaves the cylinder you have to get new rings, then of course the cylinders need to be ridge-reamed and honed. Is this correct about rings? The engine doesn't have a lot of miles on it, probably under 5000 miles, I'm guessing not enough to warrant re-boring and going to bigger pistons.
Also, any recommendations for a target gap for the various rings? Or do you have any experience or opinions on whether this particular blower makes enough extra power for ring gap to be a concern?
Thanks!
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
Put 'em back in the same holes on the same pistons and you'll be fine.
"Breaking rings in" is a misnomer, it should be "breaking cylinder walls in" since rings don't wear to fit the cylinders but the cylinders/finish definitely wears to fit the ring profile. Rings are hard as ****, cylinder walls are soft.
"Breaking rings in" is a misnomer, it should be "breaking cylinder walls in" since rings don't wear to fit the cylinders but the cylinders/finish definitely wears to fit the ring profile. Rings are hard as ****, cylinder walls are soft.
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
First if it's been running OK with no signs of detonation or blowby..I'd probably leave it alone. Just keep the tune and temps good and have fun.
But...you can put them back in there IF you are extremely careful with them. Don't hone the cylinders. I'd open them up following Wiseco's specs.
But truthfully I'd be more worried about those hypereutectic pistons. Definitely stay to the wide side of things on the top one and make sure your tune is spot on with no detonation. I'm assuming those rings are a moly ring...so detonation will kill them quickly. Look for cylinder wear spots where the rings are sealing perfectly. If there was even a little blowby...it will go up a lot with boost.
But...you can put them back in there IF you are extremely careful with them. Don't hone the cylinders. I'd open them up following Wiseco's specs.
But truthfully I'd be more worried about those hypereutectic pistons. Definitely stay to the wide side of things on the top one and make sure your tune is spot on with no detonation. I'm assuming those rings are a moly ring...so detonation will kill them quickly. Look for cylinder wear spots where the rings are sealing perfectly. If there was even a little blowby...it will go up a lot with boost.
- 004 x 4.00in bore = 0.016 inch ring gap
- Modified or Nitrous Oxide - 0.005in x 4.00in bore = 0.020 inch ring gap
- High Performance Racing - .0055in x 4.00in bore = 0.022 inch ring gap
- Racing with Nitrous/Turbo - 0.006in x 4.00in bore = 0.024 inch ring gap
- Racing Blower/Supercharger - 0.007 x 4.00in bore = 0.028 inch ring gap
- Street - 0.005in x bore size
- Modified or Nitrous Oxide - 0.0055in x bore size
- High Performance Racing - 0.0053in x bore size
- Racing with Nitrous/Turbo - 0.0057in x bore size
- Racing Blower/Supercharger - 0.0063in x bore size
Last edited by 427Hotrod; Jan 18, 2020 at 12:06 AM.
Le Mans Master
Joined: Sep 2001
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From: Unreconstructed, South Carolina
OP bp
Myself and many others have reused rings ... and Not because we couldn't find more; Nor because we were broke, cheap or stupid ... this done on weekly series race motors when we freshened them.
Those are motors that are monitored closely throughout their season. Turns out, If the motor shows no sign of ring/bore issues both before and after inspection they can be reused because they have proved they are sealing good. New ones might not seal as well.
There's a lot to inspect and measure which requires an experienced, trained eye and high-precision gaging; failing that, the motor won't live.
Seems you're somewhat inexperienced and working with a Street motor with a little blower atop Hypers. I suggest you do Not reuse rings and (as said) perhaps install Forged with thin metric ringpak and perhaps even a Steel top ring.
If you've the demeanor & grit for it, suggest find a local circletrack crew that needs a volunteer gopher; they cannot tolerate a "sophomore" so do some reflection before you jump. That's where you can begin the hands-on learning process.
Myself and many others have reused rings ... and Not because we couldn't find more; Nor because we were broke, cheap or stupid ... this done on weekly series race motors when we freshened them.
Those are motors that are monitored closely throughout their season. Turns out, If the motor shows no sign of ring/bore issues both before and after inspection they can be reused because they have proved they are sealing good. New ones might not seal as well.
There's a lot to inspect and measure which requires an experienced, trained eye and high-precision gaging; failing that, the motor won't live.
Seems you're somewhat inexperienced and working with a Street motor with a little blower atop Hypers. I suggest you do Not reuse rings and (as said) perhaps install Forged with thin metric ringpak and perhaps even a Steel top ring.
If you've the demeanor & grit for it, suggest find a local circletrack crew that needs a volunteer gopher; they cannot tolerate a "sophomore" so do some reflection before you jump. That's where you can begin the hands-on learning process.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Jackson rebuilds race motors and I used to as a job. I used to meticulously file fit the rings to what ever size bore using tables on the use. I found that during a short period of time , let's call it a break in period when the cylinders have had a hone job. That is when you probably have the most ring ware. The cylinder being softer wares before the rings, but I have noticed a definite enlargement of the ring gap.
If piston heat is consideration. I always have my piston tops coated with a thermal coating. All real race motors usually come with moly sides and thermal tops.
If piston heat is consideration. I always have my piston tops coated with a thermal coating. All real race motors usually come with moly sides and thermal tops.
Burning Brakes
Joined: Dec 2017
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2023 C3 of the Year Finalist - Modified
If you’re just planning on using it as a street car, not drag racing it, I personally would ensure the AFR is no where near a lean condition and just leave it be. A 142 blower makes like 5-6 pounds boost? I don’t think it’s an issue. Just my opinion though.
as long as you’re not lean I don’t think you’re going to get combustion chamber temps high enough to cause disaster.
I have a friend that run 14 pounds boost on stock ring gaps, it’s been working for 4 years.
as long as you’re not lean I don’t think you’re going to get combustion chamber temps high enough to cause disaster.
I have a friend that run 14 pounds boost on stock ring gaps, it’s been working for 4 years.
