<VV> RE:found cause of damaged piston

[Craig Nicol]

Ray said: <snip>
I found the answer to why I have a smiley face on my #1 piston top....  The
"lock ring" or "retainer clip" is missing off one of the lifters.  The
lifters and cam are in new condition so I hate to install a new set but I
dont know what brand or type the lifters are so I cant very well replace
just the one.  I'm hoping to find a way to just get the clip and reinstall
it.  I also checked the pushrods etc on that cylinder and found no other
signs of damage. <unsnip>

Craig replies:
I doubt that the missing lifter retainer is the cause. It would have to jump
out of the oil sump and fly around the back of the car until it entered the
air cleaner, when through the carb and turbo and into the cylinder; not very
likely.  OTOH, the smile in the piston looks just like what (as Spence said)
you get when a valve seat drops, then gets hammered back into position.
Perhaps this happened on a prior cylinder head, perhaps this head is the
culprit.  Remove the valve that's aligned with the smile and check the seat.
If the seat is perfectly seated (the seam is about 1/4" down, it was
probably another head. If there's any gap or ridge, it's time to have that
seat fixed. 

Re cam. Go ahead and change the lifter. New lifter on used cam is no
problem. Coat the base of the lifter with moly cam lube.
Craig Nicol