Broken Pistons....Help!!

[MKEDF]

We brought out the pistons, and found out two of them had broken rings, and Broken Pistons!!..

But only two of them...funny thing is that rings are tearing appart just to move them, as well as pistons are, right on the ring holding area...

Is this isolated failure, or something else is causing such a mess...

Give me a hand, and feel free to speak your mind...

Mick

amazed rookie with rebuilds...

[88-diamondblue]

Detonation is what causes this. Hopefully other with more knowledge on this will chime in.

[euro911sc]

Exactly what happened to me:

And the pieces came a tumblen' down...

Cylinders were ok though.

Best regards,

Michael

[cstreit]

You don't mention what type of car this is, but I would assume a Turbo, as these guys mentioned it's almost certainly detonation (knocking or bad pinging).

I'd also seen this once on an NA engine where the piston cooling squirters were blocked and the piston overheated, there was a lot more skirt damage evident than on your piston, where they look "fine..."

[Steve@Rennsport]

Those do not look like Turbo pistons to me but I see damage from detonation.

Overly advanced timing, poor gas, lean fuel mixtures are all contributors to this phenomenon.

[SCOTITUDE]

Hey, I got the same exact piston sittin on my desk!!!!Welcome to the Mahle ashtray club.

[bruceb]

mee too

[cstreit]

Originally Posted by Steve@Rennsport

Those do not look like Turbo pistons to me but I see damage from detonation.

Troof. CIS pistons now that I look. These still have quite a bit of room for error, but *****ty gas and "someone" getting a little happy with the timing could do it fer sure!

[SCOTITUDE]

went to JE's. if anyone needs replacements I got 5 good pistons waiting for a new home.

[MKEDF]

Just Went to the machine shop, they measured the pistons and said they are 2mm oval, out of shape..

Cyls are okay just polised them by the same machine shop willing to buy a set of P&C not shure about the pistons, but two of them are broken..

By the way they belong to a 3.0 SC 1978

Any one has a set of Pistons i can use? or willing to trade or something?

Best..

PS the Machinist said i could have been about overheating.....Thoughts??

[bruceb]

Originally Posted by Steve@Rennsport

Those do not look like Turbo pistons to me but I see damage from detonation.

Overly advanced timing, poor gas, lean fuel mixtures are all contributors to this phenomenon.

does this sort of damage happen quickly with one bad tank of gas, or is it incremental over a long time?

[MKEDF]

As i have inquired, this problem was caused by the oil on the car it was too hot and lost itīs lubricant properties (The guage was not on overheat mark but close...)

The Pistons overheated and lost shape, which conducted to the disintegration of the rings, and deformation of the pistons...

Fortunately no scratches happened to the Cylinders and they are under condition of service..

So im buying a set of used P&C`s matched together so no mistake is done while assemble..

This set of Cyls are for sale, they have been measured and polished and still under service conditions...

Any one interested on trade or Buy??

PM me...