It seems I have a little piston slap in one of my cylinders. Is this a real serious problem ? Engine is a 396.
Thanks,
Fred

Warm or cold? If it's when the engine is cold and you have forged pistons then it's common. Otherwise it could be a wristpin or a seriously worn cylinder

Dave

When the engine is warm. It almost sounds like a tappet needs adjusting. Not very loud but a ticking sound.
Thanks ,
Fred

Sounds like you have a cracked piston skirt. Piston slap sounds more hollow.

Dave

Could be very serious. Time to do some inspecting. Might want to pull the head. I had a tic like that and the piston was cracked.

Fred..a cracked skirt will sound like a top end knock off idle and more noticeable under light to heavy throttle load.Kinda like a diesel knock..but unfortunetily a mechanical fail.I had 4 of 8 skirts cracked in my 427 BBC.My machine guy said this is common when the ring pack fails.I myself would pull her apart before a skirt collapses and ruins the cyl wall.

Guys, what is piston slap? R.B.