Who's there? What will make an engine knock besides main and rod bearings? The mains look OK so far (cap side) except for a little discoloration. I will look at the rods tommorrow, but I didn't see anything unusual when I turned the engine over or wiggled the rods on the crank. If I stacked a rod bearing I think I'd get more than a muffled knock, more like Bang-Bang! (been there!) The flex plate is a thick SFI approved unit. The valve train looks OK. Didn't see pieces of piston missing! o No: Any ideas for other places to look?