As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT WAS IN CRUISE AND THE RT ENGINE STARTED TO VIBRATE. AN ALTERNATE AIRPORT WAS SELECTED AND ENROUTE THE ENGINE STARTED TO LOOSE POWER. MAINTENANCE PERSONNEL REMOVED THE COWLING AND NOTED THAT THE NR 6 CYLINDER HEAD WAS SEPARATED FROM THE BARREL. CYLINDER WAS REMOVED. CYLINDER HAS MULTIPLE CRACKS EMANATING FROM THE SPARK PLUG HOLE TO THE VALVES AND AROUND THE CYLINDER HEAD. BARREL AND HEAD ARE COMPLETELY SEPARATED.