Quote: Bearings don't spin for without reason. Somewhere, somehow the bearing came in contact with the crank. Trouble shooting the cause takes some detective work. Lack of oil,detonation, aerated oil,wrong clearances, hydrauliced cylinder ,big end distortion of the rod,poor pan design. Plenty of 440 motors around running over 7000 RPM that haven't spun bearings. I would look very carefully during dis-assembly. A very knowledgeable engine builder made this statement. If your engine has to much bearing clearance you will know it. If it doesn't have enough ,everyone will know. Good luck on your diagnosis. Doug
Common causes are loss of oil (various reasons) and detonation beating the bearing up.
