N5279A

While in cruise flight at an altitude of 6,500 feet, the 1,150-hour commercial pilot noticed a rise in engine oil temperature. The pilot opened the cowl flaps and increased the mixture control, which reduced the EGT and the CHT. Approximately 5 minutes later, the engine started "running rough and sparks appeared from the cowling with loud bangs." The pilot shut-down the engine and extended the landing gear for a forced landing on a road. The airplane was unable to make the road and during the night forced landing in a mesquite covered field, the airplane sustained structural damage. An examination of the engine revealed that several of the engine's connecting rods had failed and the number one piston was found to be eroded.