As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENGINE WAS SHOWING SIGNS OF METAL IN OIL FILTER. ENGINE DISMANTLED TO FIND CAUSE OF METAL. ONE EXHAUST VALVE FOUND TO BE PROTRUDING FROM CYLINDER FARTHER THAN USUAL. EXHAUST VALVE REMOVED AND FOUND TO BE MISSING APPROXIMATELY .1250 INCH MATERIAL WHERE RETANING KEYS HOLD VALVE. (X)