rlm328

Anyone have an extra 2.8L Mahle 100 mm stroker piston they want to part with. I really do not want to buy an entire set when I only need one.

schip43

If you don't have any luck finding one, I live close to Bill Miller Racing. I can stop by and find out what they want for a one off piston.

rlm328

Thanks

333pg333

What happened Bob?

rlm328

I believe it was caused by over heating.

Found it while replacing the head gasket.

333pg333

What about the valve cut?

V2Rocket

can i have the old one? i need a cool paperweight.

rlm328

Valve kiss - the valves are are straight, already checked.

Paper weight - I am going to have it chromed as this is going to be a fairly expensive fix.

333pg333

Ok that's interesting. I knew it wasn't a machined valve cut, but contact. Things to add to mental files. We've also experienced valve kiss where the valve was reusable and thought that was almost impossible. Looking at yours it looks more than just a kiss, more like 2nd base! Yet the valve was still straight afterwards? So you've had kiss and overheating which lead to broken piston. How did the overheating occur?

rlm328

It was the #4 piston, I am assuming steam lock in the water jacket. I am installing one of LR's steam vent systems to see if I cannot eliminate this possibilty from happening. Haven't checked the rings yet, if thet were cracked and I got oil inside the cumbustion chamber that would have also raised the temp sufficient to burn it also.

Circumstances were that it was a hot day (100 F air temp - 140 F track temp) and the car was doing double duty at a DE, when it let go.

333pg333

Do you recall the sound that it made?

Chris White

Cha-Ching.... ($$$)....some how all the 'strange' noises start sounding like cash registers...

rlm328

I didn't even know this was a problem until I removed the head. All I thought I had was a blown head gasket. From the looks of the piston it may have been this way for a while, its is fairly uniformly covered in carbon and there are no real sharp corners.

And cha -ching should be more like CHA-CHING!!

billthe3

Could that valve kiss mark have been caused by the missing chunk of the piston being smashed between the head and piston?

If that missing chunk came out in one piece, would that be big enough to mess up the turbine wheen on the turbo?

How large of a ring gap were you running?

Sorry for interogation, I'm just curious.