What was found
DURING ENGINE OVERHAUL AT APPROX 922 HOURS TT. A HEAVY DUTY CRANK CASE WAS INSTALLED AT THAT TIME. SOME TIME BETWEEN 25 AND 58 HOURS AFTER O/H, A MECHANIC NOTICED THAT A THROUGH BOLT AT THE NR ONE CYLINDER HAD BROKEN AND WAS MISSING. THE ENGINE WENT BACK, WHERE NEW CRANKCASE HARDWARE AND A NEW NR 1 CYLINDER WAS INSTALLED. THE MECHANIC INDICATES THAT THE TORQUES WERE APPLIED METICULOUSLY TO THE BOLTS. AFTER 8 HRS OF OPERATION THE SAME BOLT BROKE AGAIN. THE ENGINE MFG IS GOING TO ISSUE A NEW CRANKCASE AND CYLINDER TO THE ACFT OWNER.