Low tension ring?

[88bluestar]

The problem that usually occurs with a out of round bore using low tension oil ring is it will push alot of oil into catch can.
Measuring with a dial bore gauge doesn't tell the whole story.
I would bolt cylinder head to block, sit in a 2nd ring at desired gap and shine a light from behind the ring and see how it looks.
You can use a standard tension oil ring which might be a better option.

I agree. I would run the ball hone a few more passes with faster up and down motion to put more crosshatch in it. If this is a street engine I would definitely use a standard tension oil ring. You will have oil consumption with a low tension ring on the street.

Stock class rules with some wiggle to the rules on engine. top rpm is 6200 rpm rev limit.

[88bluestar]

Would the Sealed Power Plasma-Moly Piston Ring Sets E-921K40 be the way to go as far as a std tension set?

https://www.summitracing.com/parts/slp-e-921k40
or
https://www.summitracing.com/parts/mah-41858cp040

[88bluestar]

The problem that usually occurs with a out of round bore using low tension oil ring is it will push alot of oil into catch can.
Measuring with a dial bore gauge doesn't tell the whole story.
I would bolt cylinder head to block, sit in a 2nd ring at desired gap and shine a light from behind the ring and see how it looks.
You can use a standard tension oil ring which might be a better option.

So far two cylinders have very faint light visible, and both are outboard part of the cylinders.

[steve cowan]

Did it have low tension rings already?

[88bluestar]

Did it have low tension rings already?

It had low tension rings originally, but I got a standard tension set, and used a new 2nd ring to check. Obviously the gouges are playing a part in lifting the ring off the cylinder wall. Would perhaps a 3 stone finger type hone work better to the knock the peaks from them down. Just wondering at this point. They conform fine in the cleaner cylinders with no gouges, with no sign of light behind the ring.

[steve cowan]

If it was mine and I wanted to run low tension oil ring I would get machine shop with profilometer to torque plate hone to suit ring pack.

[88bluestar]

Plan to just run the standard tension rings. Same procedure for them?

[Old School]

If you try to get all the scratches out chances are you will have too much clearance. Just hit each cylinder a few times with a little faster up/down motion to get the crosshatch at about 45 degrees, make sure your end gaps on the rings are sufficient and assemble the engine.

The scratches look bad but most likely will not cost you very much power. Remember after the first 2 inches the exhaust valve is opening, give or take a little.