What was found
CYLINDER ASSY HAD EXTREME CLEARANCES BETWEEN VALVES AND VALVE GUIDES WHICH IS NOT INDICATIVE OF 307.0 HOURS OF OPERATION ON A CYLINDER ASSY. UTILIZING USAF SPECS, I.E., SODIUM FILLED DOME TYPE EXHAUST VALVES AND CLOSE TOLERANCE STEEL VALVE GUIDES. ALSO, EXCESSIVE PISTON TO CYLINDER BARREL SCUFFING. IN ADDITION, PISTON ASSY IS A FAA PMA P/N WHICH WHEN THIS ENGINE WAS OVERHAULED IN 1972, HAS ALREADY BEEN CHANGED, BUT THE ENGINE RECORDS DO NOT REFLECT THIS. THE R2800-99/52/101/103W O/H AND PART MANUALS SHOW SPECIFIC AND NON-SUBSTITUTABLE P&W P/N'S FOR THE PISTON ASSY. IN THIS ENG POS, THIS CYL ASSY SHOWS IN EXCESS OF 1,000 HRS OF OPER USAGE.