As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON ENGINE SHUTDOWN A SUCKING SOUND WAS HEARD AS ENGINE DIED. CYLINDER COMPRESSION CHECK WAS 0/80. AFTER STAKING THE VALVE THE COMPRESSION WAS STILL 0/80. AIR WAS HEARD COMING FROM THE EXHAUST PIPE. AFTER REMOVING THE EXHAUST STACK FROM THE CYLINDER, A CRACK AROUND THE VALVE STEM WAS NOTICED BY THE MX. CYLINDER WAS REMOVED FROM THE ACFT AND A SERVICEABLE CYLINDER WAS INSTALLED. VALVE WAS REMOVED FROM CYLINDER AND A CRACK WAS SEEN AROUND ABOUT 2/3 OF THE VALVE FACE. THE VALVE REMAINED INTACT.