As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED RIGHT ENGINE RUNNING ROUGH. INVESTIGATION FOUND NR 4 CYL HEAD SEPARATED FROM BARREL. THE CYLINDER HAD BEEN INSTALLED 148 HOURS BEFORE. RECENTLY OVERHAULED. TOTAL TIME ON CYLINDERS ARE NOT RECORDED. SUBMITTER RECOMMENDS THAT CYLINDERS BE SCRAPPED AFTER THEIR SECOND RUN OR TIME LIFE LIMIT BE ESTABLISHED BY THE MFG ON CURRENT PRODUCTION ENGINE.