20230118001569A

^PRIVACY DATA OMITTED^ DEPARTED KYNG (YOUNGSTOWN/ WARREN REGIONAL AIRPORT) ENROUTE TO KYIP (WILLOW RUN AIRPORT). DURING THE CLIMB AROUND 6000 FEET THE PILOT NOTICED OIL COMING OUT OF THE RIGHT ENGINE COWLING. AT AROUND 7000 FEET THE RIGHT ENGINE BEGAN TO RUN ROUGH. PILOT ELECTED TO SHUT DOWN AND SECURE THE ENGINE. THE PILOT THEN DECLARED AN EMERGENCY AND ASKED ATC FOR VECTORS TO THE NEAREST AIRPORT. ATC VECTORED THE AIRCRAFT FOR THE RNAV/GPS RUNWAY 11 AT GEAUGA COUNTY AIRPORT (7G8). THE PILOT PERFORMED THE APPROACH WITH THE GEAR DOWN AND FLAPS UP TO ENSURE THE AIRCRAFT WAS UNDER CONTROL. PILOT STATES THAT THE APPROACH SPEED WAS AROUND 120 KNOTS. NORMAL BLUE LINE SPEED IS APPROXIMATELY 108 KNOTS UNTIL SHORT FINAL THEN SLOWING TO AROUND 90 KNOTS. WITH THE RIGHT ENGINE PROPELLER FEATHERED AND ZERO FLAPS THE INCREASED AIRSPEED CAUSED THE AIRCRAFT TO TOUCH DOWN HARD AND LIKELY LONG. THE AIRCRAFT WAS UNABLE TO STOP ON THE REMAINING PORTION OF THE 3500 FOOT RUNWAY. AIRCRAFT LEFT THE PAVED RUNWAY SURFACE AND TRAVELED ABOUT 700 FEET PAST THE END INTO A FARM FIELD. THE LANDING GEAR COLLAPSED AND DAMAGE OCCURRED TO THE LEFT WING, NOSE AND LEFT ENGINE PROPELLER. THE RIGHT ENGINE COWLING HAD OIL COVERING A GOOD PORTION OF THE COWLING FROM THE FRONT TO AT LEAST MID WAY BACK. VISUAL INSPECTION THROUGH THE OIL DIPSTICK DOOR OIL WAS COVERING THE TOP OF THE ENGINE CASE. CLOSER INSPECTION AFTER THE AIRCRAFT WAS RECOVERED REVEALED A CRACK IN THE ENGINE CASE JUST ABOVE THE NUMBER 5 CYLINDER. THE R/H ENGINE WAS DISASSMEBLED AND THE DETERMINING FACTOR WAS THAT THE NUMBER 5 CYLINDER WAS EXPERIENCING DETONATION WHICH BURNED A HOLE IN THE PISTION. THE HOLE IN THE PISTON ALLOWED COMPRESSED CYLINDER GASES TO ENTER THE ENGINE CASE WHICH CAUSE THE FRONT SEAL TO BLOW OUT AND CREATED THE OIL LEAK. THE NUMBER 5 CONNECTING ROD SIEZED AND BROKE DUE TO OIL STARVATION. WHEN THE CONNECTING ROD BROKE IT CRACKED THE ENGINE CASE ABOVE THE NUMBER 5 CYLINDER. THE PILOT AND 5 PASSENGERS WERE UNINJURED.