As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTED NEW CYLINDER ASSY. AS RECEIVED. FOUND INSIDE DIAMETER OF EXHAUST VALVE GUIDE TO BE BELOW MINIMUM MFG. SPECS. AND VALVE SEAT MACHINING NOT CONCENTRIC. PRE-SIZED GUIDES ARE USED ON THIS UNIT AND 5 OTHERS IN THIS BATCH INSPECTED. ALL UNAIRWORTHY. ALL BALL SIZED. ALL BELL MOUTHED.