Street miles / longevity on super thin rings

Super thin to me meaning less than .043" .
Good compression check after 10,000 miles ?
Info anyone ?

Check some high performance OEM engines. They come from the factory with thin rings these days.

.043" would be huge in todays engines that go 180,000 miles

It's all about the cylinder finish. With the proper finish, tension and oil, thin rings can go far beyond what they did in the past.

Fuel management plays into this, I think. The OE stuff that can go +250k miles on thin rings are EFI.

I agree with that.

Yes, and probably other things too. Maybe ringland depth, ring- land clearance, cylinder finish, materials of consruction, piston to wall clearances - hot and cold, skirt lenght, motor rpm, compression/cylinder pressure, and probably a bunch of other quality and quality control aspects.

I would see no reason at all to run a 5/64" or 1/16" ring in this day and age.

0.043" would be the thickest I'd want to go if I had the choice.

What piston manufacturer for these new thin rings?

What about piston weight? Most new applications are super light weight compared to a stock 440. That can’t be good for skinny rings. Efi would help but most old Musclecars still run carbs.

I can’t think of a reason that piston weight would have any bearing on ring wear/ problems.

The new 5.7 hemi use a 1.2 mm top and 2nd ring so I don’t think you will have a problem running a thin ring

OEM engines are tuned for low-end, upshift sooner, and do 1500 rpm on the highway, that's why they last so long. Already mentioned, precise timing and fuel injection also helps them last forever.

My opinion, if you don't have overdrive, have anything over a 3.08 rear end, and run a carb, thin rings would not last as long as stock rings.

^ Most common oem engines are low rpm but the high rpm oem engines out there run thin rings and don't seem to wear out fast.

^ And how long does a Viper, Mustang, or Challenger spend at 3500 rpm out on the highway or in town for that matter? Almost never. Maybe 5% of the time in town.

How long does a 340, 440, 426 with 3.91's spend at 3500 rpm? All the time. Double the engine speed is double the wear.

I have 2 drag weeks and a total of maybe 3500-4500 miles on some 1.5MM rings. Car leaked down 3% after its first test drive and it still leaks down the same as of a month ago. 4.10s no overdrive but it does have EFI. This was a CNC machined block with a Diamond hone from Shady Dell back in 2015.

Are 3.0, 1.5 and 1.5mm ring packs considered thin?

I was talking about high rpm factory engines. (stuff that turns 8,000+)

My Ferrari runs 4,000 rpm on the highway, engine is 26 years old. Tons of other factory engines that turn big rpm with thin rings. Of course they were designed to do that, just saying I don't think thin rings necessarily mean the engine is wearing out super fast.

I run .8mm rings. 400 passes. Haven't leaked it. But still runs as good mph as it did when it was assembled.
Doug

Every major ring manufacturer.

I was all in on these smaller ring packs. I ordered my pistons specing them but was disappointed when they came with traditional 1/16,1/16,3/16 grooves.

And I know they last a long time in the newer cars.

But seeing again of just 8 hp on a Hot Rod video I looked at it again.

In my dirt track world they may only last one season. I run alky and the bigger rings seem to be a safer bet against fuel dilution. And my engine is not filled with the latest and trickest parts...good stuff forged pistons, Crower rods, billet crank...

And I'm the ultimate budget guy living on SS and putting my car together with good used parts and careful decisions. I can't afford a refresh every year so I am happy with what I have.

Imo, 1.2mm(.047”)and 1.5mm(.058”) aren’t really all that thin.

1.2mm is .004” thicker than .043’s, and 1.5mm is only .004” thinner than 1/16”, along with 1.0mm being only .004” thinner than .043”.

So....... how much is .004”?

About this much: