What was found
AIRCRAFT MADE AN UNSCHEDULED LANDING ON A ROAD DUE TO LOSS OF OIL PRESSURE AND ENGINE BEGAN TO SHAKE VIOLENTLY AND LOST POWER. A LARGE HOLE WAS DISCOVERED IN THE CRANKCASE ABOVE THE NR 4 CYLINDER. INSPECTION OF ENGINE COMPONENTS ON THE LIMITED TEARDOWN BY THE FACILITY THAT RECEIVED THE CORE ENGINE INDICATED THAT THE NR 4 CONNECTING ROD BOLTS/NUTS MAY HAVE LOOSENED AND BENT ALLOWING THE NR 4 CONNECTING ROD TO BECOME DISCONNECTED FROM THE CRANK PIN. THE ENGINE HAD 1138 HOURS SINCE O/H. ALL OF THE CONNECTING ROD BEARINGS, NUTS AND BOLTS HAD BEEN DOCUMENTED AS REPLACED WITH NEW APPROXIMATELY 175 HOURS AGO DUE TO CRANKCASE REPLACEMENT.