308 pistons issues....

He should not have used a dremal at all, I clean pistons in the same stuff you clean carbs in. I can't remeber what you call the stuff..decarbonizer or whatever. It's yellow and stinks real bad. But it works very well. Then afterwards I use a piston ring groove cleaner to remove the rest of the caked on carbon around the piston ring lands.

 

if you damage the pistons coating in an aircraft piston engine, the pistons are scrap. on a Ferrari ,i cannot say with 100% certainty, but the surface must be smooth or it will heat up and the ignition spark will not flow across the face of the piston properly. a irregular surface may also lead to crack and premature piston failure under load. good luck.

i think he made a mistake.