What was found
ENGINE RECEIVED FOR OVERHAUL; 3649.4 HOURS SFRM. OIL FILTER ADAPTER WAS FOUND TO BE CRACKED DURING ROUTINE INSPECTION AT ENGINE REPAIR. THE CRACK WAS LOCATED AT LOWER LEFT MOUNTING STUD BORE SPOT-FACE AT THE 10 O'CLOCK POSITION. IT APPEARS THAT THE CRACK ORIGINATED AT A SHARP EDGE, CREATED WHEN THE SPOT-FACING OPERATION WAS PERFORMED DURING PART MANUFACTURE. TOTAL CRACK LENGTH WAS APPROXIMATELY 2 INCHES. THE CRACK HAD PENETRATED INTO THE OIL PRESSURE CHAMBER OF THE ADAPTER. THIS AREA SHOULD BE CHECKED FOR A CRACK, ESPECIALLY IF A SHARP EDGE AS DESCRIBED ABOVE IS PRESENT. SHARP EDGES IN THIS LOCATION SHOULD BLENDED SMOOTH TO PREVENT A STRESS RISER IN THE ALUMINUM CASTING.