Crank Broke . wtf .

Below are pictures from a Commando racer that gave up the ghost at Sears Point, California around 1999. This is the drive side cheek. Heat discoloration on the journal is due to the rod bearing continuing to turn after failure; the journal diamater expanded a bit and had a few sharp edges whereas the rod end w/insert did not. Well it did melt away.

I recall this started life at a Mk3 crankshaft with no modofications to it. It is remarkable the roughness of the inner bore. The drill oil for the oil feed still has the burr standing proud. The end of the full bore diameter actually goes about 1/8" past the outer filet radius of the rod journal.