What was found
PILOT REPORTED LOW OIL PRESSURE. THE ENGINE WAS SHUT DOWN AND A LANDING WAS MADE AT CHILLICOTHE, MO. OIL PRESSURE RELIEF VALVE CLEANED, STARTED ENGINE AND OIL PRESSURE APPEARED NORMAL. AIRCRAFT FLOWN TO IRK, OIL PRESSURE FLUCTUATED AND WAS LOW. ENGINE WAS TORN DOWN FOR INSPECTION, RE-ASSEMBLED WITH TAGGED CRANK, NEW BEARINGS, ROD BOLTS, AND PISTON PINS.