A couple of weekends ago I accidently timed my engine at 66 degrees timing and made 2 runs. I havent't run the car in a couple of years and I forgot where my timing mark was.It is a small block 416 with 11.25-1 compression cast iron heads and moly rings I am running 110 fuel. I was running exhaust and didn't hear any detonation. It slowed down a second in the et and 12 mph. After re timing at 36 it runs fine and ET is back where it usually has been and have not seen any smoke from tailpipes. My question is would it hurt the rings or piston ring lands?

detonation kills wrist pins, rod bearings and piston skirts the worst. no way of knowing unless you pull it apart.

I would at least pull the pan and check all the bearings. If any show signs of detonation, consult your engine builder. Better to check than lose the whole motor.

I did the same thing to mine a few years back, poppin and missing at 3/4 track, ran a full second off my time. Corrected the problem and ran the reat of theyear no problems. When we did pull it apart, all was well. every motor and situation is different though.

Measure top-to-bottom clearance of rings in lands.
If they're tight, the lands got squashed.

I ones ran a street 340 a full night on a chassie dyno at 55* of timing. When i turned it down to 36 hp was almost the same but torque was up by ALOT. Didnt hear any pre ingintion.

With 110 octane I seriously doubt that engine was hurt. Just plain had no get up at high end could you damage it sure but if its quiet. Check the oil and filter for particles and then decide

I took apart the oil filter and it looked spotless so I think I will just run it. I will take it apart this winter, Thanks For the replies. Craig

I doubt anything is hurt

Go till she blows !