What was found
ON CLIMB-OUT, ENG RUNNING ROUGH, BACKFIRING, SHAKING VIOLENTLY. INSTRUCTOR LEVELED OFF & REDUCED POWER, ENG SMOOTHED OUT BUT STILL RAN ROUGH. A/C RETURNED & LANDED W/O INCIDENT. ENGINEERS IDENTIFIED A PROBLEM WITH NR 2 CYLINDER. INVEST CYLINDER FOUND EXHAUST ROCKER ARM SPLIT & BENT ACROSS UNDERSIDE BY OIL LUBE HOLE. EXHAUST VALVE LEFT IN CLOSED POSITION BY ROCKER FAILURE. INTAKE AIR INLET SCREEN FOUND BULGED OUT BUT NO OTHER DAMAGE FOUND. ENG SHOP INFORMED & NEW PARTS INSTALLED. ENG HAS 2343 HRS SINCE O/H. AFFECTED CYLINDER HAD BEEN REPLACED RECENTLY WITH AN OVERHAULED ONE & HAD ONLY FLOWN 28.0 HRS.