Damn that is pretty unhealthy. Who built the short block and any idea what the clearances measured?

 

Lol. I've had this exact same thing happen. One of those old school builders who thinks every clearance needs to be doubled. Want something done right, gotta do it yourself!

 

Yep, shotty machining or assembly. Building an engine is tougher than everyone thinks eh

 

Clearances were within stock limits. I measured more times then I care to admit. Not my first rodeo but it my first that did this.

 

I've had two cam bearings go bad and seen several others go bad..

 

ARP mains without align honing the main journals?

 

Plastigauge?

 

Nope, stock bolts and caps nothing fancy for this bottom end. I measured using dial bore guage and caliper. The split line on the bearings are where things are interesting. On the thrust, the short side of the locator tab is gone. On the other one the wear is very similar as if the crush was too much. If you look in the pic it looks like the bearing is not sitting in the cap. It is but it doesn't touch the sides anymore. The bearing is sitting there backwards I know, it stuck to the crank and I had to wiggle it off and I just sat it in there. It wasn't put together that way. I'll try to get better pics today. It started raining so I had to get my door less car back in the garage.

Another odd thing, when I built the motor I had to pry the caps off. Every time I tapped one down in there it had to be worked back out. Yet this time (engine sitting in truck still) the caps just fell out in me hand. Bolts were not loose by any means so I know they didn't work loose.

 

I looked at the back of the bearings halves. Mb3592. Std. So there weren't over sized. Can loosing two pistons warp a crank? Would a shop not see this when they balanced the crank?

 

Wow man this really sucks, I always thought a improper balance would cause this. I guess it could be a number of things that could and hope I never have to see what you are seeing. I cut my oil filter open every oil change to check and know what to look for now.

What are your plans with it moving forward? Did you call the machine shop yet?