Thanks Dick. Bearings were old stock, marked .010 Crank was turned 10 thou under,mains and rods. bearings were assembled in block and Crankshaft clearances checked and documented by a reputable engine building shop before assembly.I left the decision on whether they were usable up to them..they thought they were fine, and the clearances were spot on. Nothing but metallic looking oil in the sump. The crank has some discolouring, but no scoring as such. the Bore damage has me at a loss. I agree bearing material is too soft to do it, but what else? rings disintegrating? again, all conjecture until i rip it down.