As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE DEVELOPED EXTREME VIBRATION CLIMBING THROUGH 2,500 FEET MSL. OIL OBSERVED COMING FROM COWLING. ENGINE SHUT DOWN AND SECURED. POST-FLIGHT INSPECTION REVEALED NR 4 CYLINDER CONNECTING ROD EXITED THROUGH CRANKCASE. PISTON BROKEN. SEVERAL INTERNAL PARTS INSIDE ENGINE COWL.