On July 2, 2000, about 2052 central daylight time, a Gulfstream American AA5A, N26937, registered to an individual, made a forced landing in trees near Selma, Alabama, following loss of engine power, while on a Title 14 CFR Part 91 personal flight. Visual meteorological conditions prevailed at the time and no flight plan was filed. The aircraft received substantial damage and the commercial-rated pilot and one passenger received minor injuries. The flight originated from Selma, Alabama, a few minutes before the accident. The pilot stated he was flying from Selma, Alabama, to Monroeville, Alabama. After takeoff from Selma, while climbing through 3,500 feet, he noticed the engine oil pressure was on zero. He initiated a turn back to Selma, and in the turn, the engine lost power, dropping to about 1,200 rpm, and he noticed oil on the windshield. As he approached the airport, he realized he would not make it to the runway, and turned toward a road, for a landing. He could not make the road, and elected to land the aircraft in trees. Postcrash examination of the aircraft and engine by an FAA inspector showed that upon removal of the propeller and forward cowling, it was observed that the engine front crankshaft seal was not in place and was lying on top of the alternator. Upon removal of the No. 2 cylinder it was observed that the No. 1 and No. 2 connecting rods had separated from the crankshaft, had signs of extremely high temperature, and had damaged the crankcase. Upon removal of the No. 4 cylinder, it was observed that the No. 3 connecting rod showed signs of high temperature. The inspector stated that the damage in the engine that he observed was consistent with engine oil starvation. Logbook records showed the engine was overhauled about 280 flight hours before the accident. About 158 flight hours after overhaul and 122 flight hours before the accident the engine front crankshaft seal was replaced. (Logbook pages are an attachment to this report).