On September 22, 1996, at 1445 mountain daylight time, a Coursey Prostar PT-2 homebuilt airplane, N822CF, was substantially damaged during a forced landing near Rio Rancho, New Mexico. The airplane, owned and operated by a private owner, was being operated under Title 14 CFR Part 91. The private pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the personal flight for which a flight plan was not filed. The local flight departed from the Double Eagle II Airport, near Albuquerque, New Mexico, at approximately 1400. According to the pilot, while on a local area flight, the engine started to lose oil pressure and subsequently lost power. The pilot elected to land on a westerly heading on a 2-lane paved road. On short final, the pilot noticed a white pick up truck approaching in the opposite direction. While maneuvering to avoid the pick up truck, a high rate of descent developed and the airplane touched down hard. The airplane ground looped when the left main gear sank on the soft sand while the right tire touched down on the pavement. The airplane came to a stop on the shoulder of the road facing north. Examination of the airplane by an FAA inspector confirmed that the left wing and airframe sustained structural damage, and the left main landing gear collapsed. Examination of the engine by an FAA airworthiness inspector and the owner of the airplane revealed a fatigue crack in the oil cooler coil which allowed the oil to be pumped over board.