As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING CRUISE FLIGHT AT 1200 ASL, THE PILOT REPORTED A MISS IN THE ENGINE ACCOMPANIED WITH A REDUCTION IN CRUISE SPEED. CARB HEAT WAS SELECTED AND ENGINE CHECKS COMPLETED. SHORTLY THEREAFTER, THE ENGINE BACKFIRED 3 TIMES BUT CONTINUEDTO RUN NORMALLY BUT ROUGHLY. A PRECAUTIONARY LANDING WAS COMPLETED. MAINTENANCE INVESTIGATION REVEALED THAT THE NR7 CYLINDER HEAD HAD SEPARATED FROM THE BARREL.