Hi all!
Ive got a 4g64 block with:
balance shaft deletes
machined oil squirters
100mm manley forged crank
156mm manley I beam rods
.080 over wiseco 1400hd coated pistons set up to about 10.5:1
deleted oil cooler
lots of other stuff that isnt very relevent

I built the motor myself and blueprinted the whole shortblock. Mains are all at .0018 clearance and rods are all .0018. Using all ACL bearings. I blueprinted the oil pump as well.

I ran the motor relatively easy for break in and never saw more than 5k rpm. after 60 miles it developed a knock. i tore it down and found a spun bearing on rod #2. I had the crank welded and reground to factory spec and mic'ed. All other bearings looked great. I deleted the oil cooler and replaced the oil pickup strainer and fully cleaned the block. i ran it again for only 20 miles and it developed another knock, but i caught it before it scored the crank. I rolled a bearing into it and it died after just 20 mins of idling.

I have removed the motor again and triple checked everything. All rods measure at .0018 ans well as all mains with the ACL bearings installed. This is checked with a line bore gauge and micrometer. I also confirmed with plastigauge. All oil galleys are clear including those in the crank. I checked them with compressed air and water.

I work on a top fuel dragster team as the bottom end guy. I am no stranger to building engines and understanding oiling systems.
We have a common problem where if we have too much timing advance in our motor, it eats bearings. Could this be an ignition related issue? Has anyone ever heard of this?? We are all scratching our heads!!