What was found
A/C EXPERIENCED SUDDEN LOSS OF POWER, LANDED SAFELY ON COUNTRY ROAD. INVESTIGATION FOUND NR 3 CYLINDER LOST 75 PERCENT OF EXHAUST VALVE FACE THAT SUBSEQUENTLY TRAVELED THROUGH THE INDUCTION SYSTEM TO REMAINING CYLINDERS. BROKEN VALVE PARTS FORCED SPARK PLUG TIPS TO CRUSH TO A NO GAP CONDITION. NR 1 CYLINDER HAD BOTH PLUGS CRUSHED, NR 2 HAD ONE PLUG CRUSHED, ENGINE BASICALLY RAN ON 2 CYLINDERS. PN OF VALVE LW OR SL19001. ENGINE REPLACED, TEST RUN OPS REVEALED INADEQUATE COOLING TO THE NR 3 CYL WITH SAME BAFFLING AS FAILED ENG. CHT IND REVEALED TEMPS TO BE ABOVE 420 DEGREE TEMPERATURE DROP IN OPERATION. SUSPECT HIGH CHT TEMP CAUSED SHORT LIFE SPAN OF VALVE.