Exhaust Valve Imprinting

[Hostile]

Tearing down my 144D and found a cracked piston (between piston grooves).I started cleaning the crud off the top of the pistons and found nice little round circles directly below where the exhaust valves would be. The circles weren't nice and polished. Could this be from exhaust erosion or am I looking at a clearance problem?
Thanks.

 

[Dean]

How much carbon was on top of the pistons?

Dean

 

[Hostile]

Probably about 1/8" of carbon on top of pistons.

 

[Dean]

Most likely due to the excessive carbon build up. The combustion chamber is quite small in a diesel engine. Probably nothing to worry about.

Avoid ether and you will not crack ring lands.

I would inspect the other pistons very closely.

Dean

 

[Hostile]

Dean,thanks for the info.