As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE PROCURED WITH -0- TSO AND CYLINDERS INSTALLED. AFTER 50 HOURS, REMOVED ALL CYLINDERS DUE TO EXCENTRIC VALVE GUIDE BORE AND THEREFORE LEAKING STEM. AT 151 HOURS TSO, ALL CYLINDERS LOW COMPRESSION (53-67 PSI). INSPECTION REVEALED DAMAGED VALVE GUIDES AND CARBON TRACES ON PISTONS.