Advice on cam failure

[blown265]

Quote:
"Almost sounds like these holes needed to be graded in size with the largest at the back running down to the smallest at the front."

That's very close the way I modify them- the two rear "primary supply" holes from block to head I open up to 9/16", and the first two rear steam holes are taken to 3/8" and 5/16". The remainder are left at a clean 1/4". Not quite graduating/grading, but the same principal as you describe.
Next block I do for myself, I'll look into taking the passages out closer to a "largest to smallest".
Regards
Paul

[stealth]

Someone dropped the cam ..Crack took time to propagate .... mark in bearing is from end of life dance just before complete failure.