As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NEW CYLINDERS WERE INSTALLED ON ACFT. 2 OF THE 12 CYLINDERS FAILED AT 25.3 TIME IN SERVICE, WITH WHAT LOOKED LIKE THE NICKEL COATING SEPARATING FROM THE CYLINDER WALLS. UPON REMOVAL OF THE CYLINDER (1 FROM EACH ENGINE), THE NICKEL COATING HAD SEPARATED AND THE PISTONS HAD EXTREME SIDE WALL DAMAGE. THE OIL FILTERS WERE REMOVED, CUT OPEN AND INSPECTED; ALUMINUM PARTICLES WERE FOUND IN THE FILTER ELEMENTS.