Crump_4

looks like its had some small detonation but not much. Have you sprayed it with nitrous before?

Twisted

Well, the man who trained me (Chuck of Chuck's Motorcycle in HB, CA) said that if there are any edges or jagged parts on the piston or in the combustion chamber, they will become hotspots, and cause further detonation. Still, your pistons don't look bad to me. The flycuts (valve reliefs) may have been throwing me off before.

88stangaruu

you can take some oven cleaner or brake cleaner to them, bring the one your cleaning to TDC and spray some oven cleaner on it (make sure its aluminum safe of course) then take a soft brush...uhh, like a tire brush and scrub them some. Make sure nothing gets down into the other cylinders obviously. And it should be good then. Just looks like you may have run a little lean before. Check your A/F ratio.

Its coming along pretty nice huh, good luck.

r.barn

Strange had this car for almost 10 years, got it from old guy who never drove it too hard.

never had nitrous or s/c or anything, and never heard any pinging or detonation while driving.
has always run like a champ.

guess i'll clean it tomorrow and see what I've really got.

noticed the first piston on that side has it a little too, but not as pronouced

hmmmmmmm..........

HACKGT350

what does detonation sound like?

r.barn

Thought it sounded like a real bad knock in the engine.

FullAuto

Needs more NX!

Twisted

Some say it sounds like change or marbles in a can, while the motor is under load. That's the closest explanation I can muster.

HACKGT350

yeah just from what you guys say, it sounds harible

FiveLiterRiceEater

it kinda looked like a valve smacked your piston..but now..it doesnt.