At about 1915 Eastern time, the Experimental airplane lost engine power while in cruise flight, and was substantially damaged during a forced landing. The Private pilot was not injured; visual conditions prevailed. The pilot reported that the airplane was descending through 2000 feet at 160 knots when the engine lost power. He turned toward a nearby airport, switched fuel tanks, placed the mixture control to full rich, and confirmed that the fuel boost pump was in the on position. The airplane continued to descend and the pilot performed a forced landing to a field. During the landing, the airplane struck a ditch and flipped over.