It was eating more than the cam bearings... look at all of the bearings in the 3rd photo provided by the OP in his original post, and, in particular, the rod bearing pair in front of the 2nd piston from the right. Almost all of the bearings are showing signs of oil starvation or something that was badly effecting the bearing surfaces.
I have to wonder if the oil gallery plugs have been left out of the front of the block.
