What was found
ENG WAS REMOVED AT 353.2 HRS SMOH AND WAS SENT BACK TO MFG FOR REPAIR DUE TO METAL IN THE OIL. AT 779.5 HRS METAL WAS FOUND IN OIL SYS. WE REPLACED ALL FOUR CYLINDERS AND CONNECTING ROD ASSY. GROUND RUN AND TEST FLIGHT CHECKED GOOD. AT 981.6 HRS TSO AND 202.1 HRS REPLACED CYLINDERS ASSY, OIL CONSUMPTION INCRESSED. WHEN SPARK PLUGS WERE CHECKED, OIL WAS FOUND ON NR 1 AND NR 4 SPARK PLUGS. REMOVED NR 1 CYLINDER AND FOUND OIL CONTROL RING BROKEN AND CYLINDER WALL BADLY WORN AND WEAR STEP COULD BE FELT AT BOTTOM TRAVEL OF PISTON. REMOVED THE NR 4 CYLINDER AND FOUND TO BE WORN BUT NO BROKEN RING. ALL CYLINDERS WERE MFG IN SAME TIME FRAME. IT SEEMS THAT IT MIGHT BE A BAD BATCH OF CYLINDERS FROM FACTORY.