As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)PILOT REPORTED A ROUGH RUNNING ENGINE ON APPRAOCH. POST FLIGHT INVESTIGATION REVEALED ONE OF THE EXHAUST VALVES HAD FRACTURED AND SEPARATED FROM ITS STEM AND DESTROYED THE PISTON CROWN AND CYLINDER CA P. THE EXHAUST VALVES ON ALL CYLINDERS INDICATED A "TULIP" CONDITION. THE FUEL AND INDUCTION SYSTEMS WERE CLEANED AND INSPECTED AND ALL NEW STEEL CYLINDER ASSEMBLIES WERE INSTALLED.