What was found
(CAN) DURING CRUISE ENGINE STARTED TO VIBRATE AND THEN STOPPED. AIRCRAFT RETURNED TO ORIGIN AND LANDED SAFELY. IT WAS DISCOVERED THAT ENGINE HAD STOPPED DUE TO #2 MAIN BEARING FAILURE. TEARDOWN REVEALED THAT THE #2 BEARING HAD TURNED IN THE CRANKCASE STOPPING THE OIL FROM FLOWING TO THE NUMBER 2 CONNECTING ROD. THE CONNECTING ROD THEN FAILED AND DAMAGED THE CRANKCASE, CAMSHAFT AND CYLINDERS. THIS CAUSED THE ENGINE TO QUIT RUNNING.