Cam Bearings

I bought the coated bearings from TA and the machine shop that put them in couldn't get the cam to fit with them in.

 

This is a pic from your first post, wth the cam. I noticed inconsistent tracking from the heel to the nose. If we are looking at it from the front, I’d say that the cam centerline is higher in the front than the rear, or the lifter bores are not 90° perpendicular and tilted toward the front.
As the spring load on the lifter increases, it’s cocking the lifter to a full contact...or, possibly the lobes have some taper. The cam/lifter locations in the block are most likely the culprit, but of course you never know till you check it all.
Start with checking the cam, of course. Roller wheel to cam misalignment is the biggest cause for tie bar and axle/bearing failure, as well as body breakage. I think cam companies take a lot of blame, that they may well shouldn’t, when those things fail.

 

What did the host bore measure, and then the bearing bore after the cam bearing was installed? I’ve seen many times where the ID measurement was OK, but the journals were misaligned. The bearing manufactures always seem to get the bad wrap.

 

I don't know. By the time the machine shop called me they had already taken them out and replaced with standard bearings. Told me one of the bearings was two or three thousands too small and couldn't get the camshaft to fit.

 

Sounds more like one of the housing bores was small. The coating wouldn’t be that thick on the bearing. It only like .0005” or so.

Probably needed your cam tunnel honed slightly. Doesn’t sound like they measured the housing bore. I’m guessing they sized the bearing a little...