What was found
PILOT (OWNER) DEPARTING FROM AIRPORT AND CLIMBING THROUGH 4,000 FEET NOTED LOUD BANG AND SEVERE VIBRATION FROM LT ENGINE. ENGINE SHUT DOWN AND SECURED AND SAFE LANDING MADE. DISASSEMBLY OF ENGINE REVEALED CRANKSHAFT BROKEN. BREAK OCCURRED AT THE REAR CHEEK OF THE NR 2 ROD JOURNAL IN THE RADII. CRANKCASE, RODS, CAMSHAFT, AND CYLINDERS ALL NOW N.G.