Black death

Any body have a definitive answer and what causes black death on piston skirts?

 

Could be many things, mostly timing related.
If you own an adjustable timing light, I for sure can tell you !

 

when the piston cant turn the crank, it digs itself into the cylinder wall, caused by many things- lean at the hit,cant carry the gear

 

As Bob said it can be many things. Assuming it has enough piston to cylinder wall clearance anything that can cause detonation. One should always check for loose header bolts, intake bolts to see if detonation is taking place. If only the bolts in one area get loose that may correspond with a particular cylinder. Of course my favorite is the TDC marker not being accurate. I have had more than a handful of customer engines with a 1 or 2 degree variation. If you are running on the edge that can as well as the timing light cause a problem. Adjustable lights are emulators and not accurate. Simple is better.

Of course not enough fuel is a whole other deal.

 

There was a problem with a racer I know of. Thought he knew everything,he spent 2 months trying to figure it out. Kept telling him to check the height of the sleeves to the block. Well guess what. he had someone deck the block, and set the sleeves . No more problem in that area now he is letting someone who never ran a blower motor to tell him what to run. So far 2 broken snouts & pushed out head gaskets. Wants to run 12+ comp. with 20+ over. no O -rings . It is one thing to break parts. Another one to keep doing it, & still won't listen to what people are telling him. I gave up, & just let him spend money. Just one chapter in this ugly book. Don