I got called in to a tractor puller's shop one evening to bring my portable line-bore machine and try to cure a crankshaft lockup problem when the main bearings were torqued on a blown 426 Hemi. Even after the line-bore, the crank would lock up every time the thrust bearing was tightened. After several diagnosis attempts, we found that the main bearing cap was bent, and was taking up all the clearance on the thrust flange as it was tightened. It turned out that the block had come out of a car that was involved in a hard front end wreck, and the crankshaft had taken a 100-MPH lick on the vibration damper. All that thrust had been transfewrred to the main bearing flange, bending thr cap. A news main cap and a little line-boring solved the problem.
Jerry
