As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON INITIAL CLIMB OUT PILOT NOTICED A VIBRATION AND ELECTED TO RETURN FOR LANDING. THE NR2 CYLINDER WAS FOUND CRACKED FROM THE SPARK PLUG, PAST THE EXHAUST VALVE AND APPROXIMATELY 75 PERCENT AROUND THE HEAD / CYLINDER. THE CYLINDER HAD GOOD COMPRESSION (72/80) 2 MONTHS PRIOR. THIS CYLINDER WAS INSTALLED 9-2008 AFTER BEING REPAIRED.