Accident Sequence
Near the end of the first flight following the installation of an overhauled engine, the pilot observed a rapid drop in oil pressure. Shortly thereafter, the engine seized.
Post-Accident Findings
After the accident, the left side lower exterior fuselage was found covered with fresh oil. The oil smear originated near the oil breather line. The engine cowl baffle seals had been installed incorrectly. Less than one quart of oil was found in the engine sump.
On the external rear sides of the #3 and #4 cylinder barrels, an oval area of heat distress was noted. The crankshaft and piston rods exhibited progressive heat distress on all rod bearings and crankshaft journals. The #1 rod showed the least heat signatures, while the #4 rod displayed the most severe heat damage. The #3 rod cap was found loose in the engine; examination of the cap bolts revealed severe necking signatures at the point of tension failure.
A micrometer was used to measure the cylinder barrels for roundness. The #3 cylinder was found to be outside the factory specification by 0.002 inches.