Are thin piston rings worth horsepower?

[GARY C]

They found 8 hp going from 5/64in rings to 1.2mm rings in a street engine.
But if Grumpy's theory is correct that you will gain 5 hp just by putting new rings in a freshly dynoed engine then they really only gained 3.
https://www.youtube.com/watch?v=-29IWc-zrv8

[MELWAY]

They way nascar and pro stock keep pushing boundaries with thin rings there must be a fair amount of gains in it

I’d say the more rpm and hp/ cu in the more the gains would show up on a dyno

[GARY C]

They way nascar and pro stock keep pushing boundaries with thin rings there must be a fair amount of gains in it

I’d say the more rpm and hp/ cu in the more the gains would show up on a dyno

Yes they said they thought higher rpm would show more.

[travis]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

[TAG]

Im also interested about this subject. Speaking strictly about street engines, with 6000rpm limit, and 350-400hp from 350-383cui engine.

How much in reality we are looking to lose with the old 5/64 ring-pack compared to modern thin ring? Especially at the 2000-3000rpm range where many street engine spend most of their time in reality. Somehow i have a hunch that its not so big difference than some let you believe by stating these old rings obsolete and archaic, when marketing the latest gizmos..

[MELWAY]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

I would say no it’s probably the opposite
Most thin rings are of steel and or coated
Also OEM are using thin ring technology with very long life

[mag2555]

Thinner rings, I.E. lighter mass gets to have a big effect above 7000 rpm , and as you might surmise as the motors stroke gets larger.

[travis]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

I would say no it’s probably the opposite
Most thin rings are of steel and or coated
Also OEM are using thin ring technology with very long life

Yes, the OEM’s use them, but the big difference (besides better machine work) is fuel injection and computer controlled spark timing. Better fuel management has to be worth something

[BOOT]

Thin is in

[jed]

X2

[psychomotors]

Im also interested about this subject. Speaking strictly about street engines, with 6000rpm limit, and 350-400hp from 350-383cui engine.

How much in reality we are looking to lose with the old 5/64 ring-pack compared to modern thin ring? Especially at the 2000-3000rpm range where many street engine spend most of their time in reality. Somehow i have a hunch that its not so big difference than some let you believe by stating these old rings obsolete and archaic, when marketing the latest gizmos..

This is what I am interested in , also.

[PackardV8]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

I would say no it’s probably the opposite
Most thin rings are of steel and or coated
Also OEM are using thin ring technology with very long life

Every part in an OEM engine has been tested and retested for a matrix of durability/performance/cost. Thin rings are used in OEM builds because they perform better in durability/performance/cost than the 5/64" old school.

To experience the reduction in ring drag, build a current thin ring engine, spin it over and it can be turned by hand. Then the next build is an antique with four 3/16" rings. It will require a long breaker bar to spin that old sucker.

jack vines

[CGT]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

I would say no it’s probably the opposite
Most thin rings are of steel and or coated
Also OEM are using thin ring technology with very long life

Every part in an OEM engine has been tested and retested for a matrix of durability/performance/cost. Thin rings are used in OEM builds because they perform better in durability/performance/cost than the 5/64" old school.

To experience the reduction in ring drag, build a current thin ring engine, spin it over and it can be turned by hand. Then the next build is an antique with four 3/16" rings. It will require a long breaker bar to spin that old sucker.

jack vines

I recently did just that, but in reverse. It had been a long time since I had anything to do with a 5/64 3/16 setup. I just did one. Even just running them through a tapered ring compressor...hadn't had to tap a piston in like that in awhile. Very pronounced difference. And that was even with a slightly backcut top ring and a lower tension expander.

I just can't see the negative in the thin stuff with the exception of cost of course. But if you don't have 150.00 to start getting into some decent ring packs...well. In OE applications the thinner rings are more inclined to stick in the grooves over time with poor maintenance habits. But a lot of times this at mileage's similar to where you would be replacing the old ring packages....along with machine work.

[GARY C]

For an under 6500 rpm street engine with a carb, would the thinner ring pack have a shorter life expectancy? Many machine shops I have spoken with seem to think so.

I would say no it’s probably the opposite
Most thin rings are of steel and or coated
Also OEM are using thin ring technology with very long life

Every part in an OEM engine has been tested and retested for a matrix of durability/performance/cost. Thin rings are used in OEM builds because they perform better in durability/performance/cost than the 5/64" old school.

To experience the reduction in ring drag, build a current thin ring engine, spin it over and it can be turned by hand. Then the next build is an antique with four 3/16" rings. It will require a long breaker bar to spin that old sucker.

jack vines

In the video I posted the thinner rings cut break away tq in half, I would tend to think in high mileage applications they would reduce or eliminate bore wear and ring grove at the top of the bore.

[camaro/holland]

Have been looking at this for some time, so interested in your opinion about using thin rings on pistons with a standard ring groove and a spacer. Will you have the same gains, any drawbacks to going this way? Thanks.