[rich]

The outside diameter of the stub is 23mm. The outside diameter of the cam at the front bearing surface is just under 30mm. The wall thickness after drilling a hole through the new stub for the sprocket bolt is 6mm.

My cylinder walls in my block are thinner than 6mm and under way more stress. It looks like these cams break because they are cast. A steel billet would never do this.

I was thinking my repair idea may even work better if I did the same repair only cut the cam off at the flange at the rear of the bearing support. Then drill and thread a repair section onto the cam at the flange. The threaded section then wouldn't be hollow. The repair stress would be supported by the bearing rather than hanging off the end of the cam.

These cams are only surface hardened. The center is drillable and tapable