[steve25]

Yes it does look like a crack below the top ring.

And here’s two other things.

The rings used are not even up to factory quality.

I see only a Moly top ring on those pistons where as the factory rings where a far better Moly face top and second ring.

The rods are old type that still have the unnecessary oil hole spurt hole in the parting line of the big end.

Moly face rings need to be installed very carefully so as to not scratch there face and the cylinder wall finish must be what’s needed for such a ring face.

[TRADERMIKE 2012]

Originally Posted by steve25

Yes it does look like a crack below the top ring.

And here’s two other things.

The rings used are not even up to factory quality.

I see only a Moly top ring on those pistons whereas the factory rings were a far better Moly face top and second ring.

The rods are old type, that still have the unnecessary oil spurt hole in the parting line of the big end.

Molly face rings need to be installed very carefully so not to scratch their face or the cylinder wall finish. A smooth finish must be what’s needed for such a ring face.

Mikes reply:

"Why did the Top Compression ring Break into uneven parts anyway, on about 5 combos of Piston and Ring sets?

[TRADERMIKE 2012]

Originally Posted by TRADERMIKE 2012

Mikes reply:

"Why did the Top Compression ring Break into uneven parts anyway, on about 5 combos of Piston and Ring sets?

You said:

Molly face rings need to be installed very carefully, so as not to scratch their face or the cylinder wall finish. A smooth finish must be what’s needed for such a ring face.

Mikes reply:

Does that mean that after Boring or simply Honing, one would "not" cross hatch the cyl. wall?

Thank you in advance.

[400 Lemans]

I think the rings broke when you knocked the pistons out and the top ridge on the cylinders was a little to big. The rings grabbed on the edge of it. Sometimes you have to use a ridge reamer when possibly reusing the same pistons.

[Schurkey]

Originally Posted by 400 Lemans

I think the rings broke when you knocked the pistons out and the top ridge on the cylinders was a little to big. The rings grabbed on the edge of it. Sometimes you have to use a ridge reamer when possibly reusing the same pistons.

I completely agree that the ridge is likely the cause of the broken rings.

To my way of thinking, a ridge-reamer is a tool for destroying cylinder walls. It's really easy to get too aggressive and carve too deeply. In my world, the pistons get knocked-out and thrown in the scrap-metal bin if they're damaged by the ridge. I let the boring-bar deal with the ridge.

MOST OEM pistons are not worth saving--they're heavy, they're cast to be cheap, they're maybe not shaped properly for optimal compression and flame travel...modern pistons can be so much better than what came in the engine to begin with.

[TRADERMIKE 2012]

Originally Posted by Schurkey

I completely agree that the ridge is likely the cause of the broken rings.

To my way of thinking, a ridge-reamer is a tool for destroying cylinder walls. It's really easy to get too aggressive and carve too deeply. In my world, the pistons get knocked-out and thrown in the scrap-metal bin if they're damaged by the ridge. I let the boring bar deal with the ridge.

MOST OEM pistons are not worth saving--they're heavy, they're cast to be cheap, they're maybe not shaped properly for optimal compression and flame travel...modern pistons can be so much better than what came in the engine to begin with.

Mikes reply:

I never considered to ridge reem the top of the cyl. prior to removing the pistons. Is that Protocall when dismantling the motor? I always thought that came later, as a matter of fact one would Bore first and that should remove the ridge before Honing and lastly cross Hatching the cyl. , wall with x's.