What was found
NEW SUPERIOR CYLINDERS WERE INSTALLED AT ROUTINE OVERHAUL. AT FIRST OIL CHANGE, SIGNIFICANT AMOUNTS OF ALUMINUM WERE FOUND IN THE OIL FILTER. AFTER 5 MORE FLIGHT HOURS, THE FILTER WAS AGAIN INSPECTED, MORE ALUMINUM WAS FOUND. THE ENGINE WAS DISASSEMBLED AND INSPECTED. IT WAS FOUND THE OUTER SPRINGS (VALVE) WERE RUBBING AGAINST THE SPRING POCKETS, REMOVING ALUMINUM FROM THE INSIDE OF THE HEAD CASTING. THIS CONDITION WAS FOUND IN SEVERAL OTHER ENGINES WITH SUPERIOR MILLENIUM O-235-L2C CYLINDERS.