Engine Power Loss
The airplane was cruising at 10,500 feet when the engine began to run rough. After 30 seconds, the engine seized and would not turn over. At the time of the power loss, the airplane was 4 miles east of an airport. However, the pilot chose to turn toward an airport 20 miles to the north because it appeared on the 'Nearest Airport' display of the Loran equipment on board.
Forced Landing
The pilot determined he would not reach the intended airport and performed a forced landing to a field.
Post-Landing Inspection
Removal of the engine cowling revealed an oil-soaked engine compartment. Two quarts of oil remained in the sump. The oil temperature probe was free of the engine case, attached only by its electrical lead. The threaded portion of the probe and its corresponding attachment point on the engine were undamaged. The probe's copper crush washer displayed evidence of compression, but no evidence of safety wire was found on the probe or the engine case.
Recent Maintenance
The engine had been overhauled 30 days and 10 flight hours prior to the incident. The oil temperature probe, an airframe item, was removed and reinstalled during the engine overhaul.