Wiped Cam Lobe Theory - Imput Wanted:
In my case I believe the cam lobe wiped due to the lifter not spinning,and building up a hot spot . Only one lobe went bad the others looked beautiful with a nice swirl pattern. The bottom of the lifter was carved out from the cam lobe. In subsequent builds I have always made sure the lifters rotate . That was nearly ten years ago have done three builds since with no issues.Hope this info helps someone.