What was found
(CAN) AFTER TAKEOFF PILOT REDUCED POWER TO CLIMB, NOTED UNUSUALLY LOW OIL PRESSURE, AFTER FURTHER REDUCINGPOWER TO CRUISE SETTING OIL PRESSURE STABILIZED AT BOTTOM OF GREEN ARC. PILOT COMPLETED FLIGHT (10M MINS) TO BASE. OIL TEMPS & CYLINDER HEAD TEMPS NORMAL. ENGINEER INSPECTED OIL PRESSURE RELIEF VALVE FOR FOD. FOUND SMALL METAL FOD UNDER SEAT. REMOVED & INSPECTED OIL FILTER, REVEALED METAL TRACES ABOVE NORMAL CONCENTRATIONS. ENGINE REMOVED FROM AIRFRAMES TO BE INSPECTED BY O/H FACILITY.