As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE PILOT REPORTED A LOSS OF POWER AND LOSING ALTITUDE TO AIR TRAFFIC. AN EMERGENCY LANDING WAS ACCOMPLISHED AT A PUBIC AIRPORT. MAINTENANCE PERSONNEL FOUND THE NR 2 CYLINDER HAD A BROKEN EXHAUST VALVE, WITH THE PISTON AND CYLINDER DAMAGED DUE TO THE HEAD OF THE VALVE IN THE CYLINDER. THE STEM OF THE VALVE WAS STILL ON THE ENGINE. THE ENGINES WAS LAST OVERHAULED ON 08/24/1983.