Cylinder and piston damage cause..?

[67r/t4speeder]

Not to disagree with everyone, but my vote is the ring gap was too small. Notice the shiny spots in the cylinder where the ring wore, nothing like that on the adjacent one.

You get ring gap wrong with those pistons and that it exactly what happens.

[Stargazer]

What other kind of rattle is there??
Actually, I'm interested in knowing what they told you caused this problem?? Also, who the engine builder is??

Rattle.. Well maybe something mechanical. Like valvetrain or transmission..? However heads are new, trans is done two years ago.

They (he) thinks that it has something to do with; height of pistons, headgasket thickness, space and shape of combustionchamber, shaking of piston due to some fault... Something like that.
Think they are not absolutely sure themselves. They did the math before assembly, also measured compression ect. Never had something like this happen.
It's a shop in the Netherlands (Europe). And should know their stuff. They race a ProMod dragster......

[67440Dodge]

Google "Keith Black Piston Ring Damage" and look at pictures..

Seems like your motor is the poster child for it..


Rich wins a prize for catching it!

[Mopars & Missiles]

Not to disagree with everyone, but my vote is the ring gap was too small. Notice the shiny spots in the cylinder where the ring wore, nothing like that on the adjacent one.

Rich, don't apologize for having a different opinion, that is what makes America great, we are still (for the time being) allowed to think for ourselves. Too much PC BS, heaven forbid don't say anything to offend anyone already in the world.

As for the ring gap too tight, you may very well be correct. I saw that "chunk" missing from the top of the piston and that usually is a sure sign of a tight ring. But the "rattle" description sure sounds like detonation as well. Could be BOTH things were happening in this engine.

You get ring gap wrong with those pistons and that it exactly what happens.

Absolutely agree with you Andy! (and that isn't any PC BS either)

Rattle.. Well maybe something mechanical. Like valvetrain or transmission..? However heads are new, trans is done two years ago.

They (he) thinks that it has something to do with; height of pistons, headgasket thickness, space and shape of combustionchamber, shaking of piston due to some fault... Something like that.
Think they are not absolutely sure themselves. They did the math before assembly, also measured compression ect. Never had something like this happen.
It's a shop in the Netherlands (Europe). And should know their stuff. They race a ProMod dragster......

Yeah, I see what you mean about their explanation. Doesn't sound like they know what it was either. I noticed the cylinder walls don't look too pretty either. I think you said there is only about 200 miles on this engine, I would think you should still see a very NICE cross-hatch finish hone on the cylinders with that amount of run time. It isn't there. Throws up another Red Flag for me.

Google "Keith Black Piston Ring Damage" and look at pictures..

Seems like your motor is the poster child for it..


Rich wins a prize for catching it!

Mike, if you're giving out a prize, it probably should go to RT K_Line as he brought it up first. Rich just backed him up! (Sorry, Rich!)

[Mopars & Missiles]

New question? (But related)

Will an engine "Rattle" when the ring "end gap" is tight?? Or, does it just unexpectedly go "Bang"??? Curious as to the varying symptoms.

[markz]

Not to disagree with everyone, but my vote is the ring gap was too small. Notice the shiny spots in the cylinder where the ring wore, nothing like that on the adjacent one.

I am assuming these are hypereutectic pistons? If so, this is a very known issue. If you gap the rings to stock specs you will break the top ring gland - certainly appears that has happened here.

Edit - I missed all the responses on the second page! Looks like we all agree..............

[67440Dodge]

The more I look at it, and the more we discuss it, I think there were multiple issues going on with that cylinder.

The top of the piston looks pockmarked, which is a classic detonation sign. The skirt looks like it's got some blowby on it, but is also wiped clean where the skirt rubs against the cylinder wall. That usually indicates the piston was slapping around in the bore. Another is look at where the wear marks end, at the top it's pretty high for a top ring (the block looks like it was decked, so I'm assuming a zero deck, not a way down in the hole TRW flattop, and way too low down at the bottom for a top ring to rub (The oil rings would be out the bottom of the cylinder). But the busted piston top is a classic sign of incorrect ring gap.

The only way we'll know is if the ring gap gets measured.



As for prizes, you're right M&M (Sorry, I'm too lazy to type it all out), RT K_Line does get the prize.. I'll grant him access for 2 hours to Rich's part stash.. anything he wants, he can have..

[Mopars & Missiles]

Sounds like a damn good prize, wish I'd won that one!

[markz]

The more I look at it, and the more we discuss it, I think there were multiple issues going on with that cylinder.

The top of the piston looks pockmarked, which is a classic detonation sign. The skirt looks like it's got some blowby on it, but is also wiped clean where the skirt rubs against the cylinder wall. That usually indicates the piston was slapping around in the bore. Another is look at where the wear marks end, at the top it's pretty high for a top ring (the block looks like it was decked, so I'm assuming a zero deck, not a way down in the hole TRW flattop, and way too low down at the bottom for a top ring to rub (The oil rings would be out the bottom of the cylinder). But the busted piston top is a classic sign of incorrect ring gap.

The only way we'll know is if the ring gap gets measured.



As for prizes, you're right M&M (Sorry, I'm too lazy to type it all out), RT K_Line does get the prize.. I'll grant him access for 2 hours to Rich's part stash.. anything he wants, he can have..

If I remember correctly, the KB pistons have a pretty tight clearance. I agree with the slapping in the bore and the piston clearance should be measured to see if it is within KB spec.

In my 383 it had KB Silvolite pistons in it. The clearance was about double of what KB recommends and I saw no evidence of piston slap in the walls. This makes me believe that the clearance may be a lot bigger than recommended.

[RT K_line]

I only need 15 minutes to find a decent set of grill surrounds he has stashed away lol.