On September 3, 2004, at 1230 Pacific daylight time, an experimental Hardin Lancair 320, N320MC, registered to and flown by the pilot as a 14 CFR Part 91 personal flight, experienced a loss of engine power followed by an emergency off airport landing to an open field near Chewelah, Washington. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The aircraft was substantially damaged and the private pilot owner and commercial pilot rated passenger received minor injuries. The flight had been operating in the local area for about 30 minutes prior to the accident. During a telephone interview, both the pilot and pilot rated passenger reported that this was the first flight after the engine had been rebuilt. The flight was planned to circle the airport environment to "break-in" the engine. The engine had been operating at 75 % power for the 30 minutes and readings for engine performance and fuel consumption were recorded. The pilots then decided to land at the airport they had been circling. Both pilots reported that just after the landing gear was lowered, they both smelled a heavy odor of fuel. About two minutes later, the engine began to sputter and subsequently quit. Unable to accomplish a successful landing at the airport, the pilot elected to perform a forced landing to an open field. The aircraft's left wingtip contacted the surface first and the aircraft cartwheeled before coming to rest. Post-accident inspection of the wreckage by a Federal Aviation Administration Inspector from the Spokane, Washington, Flight Standards District Office, reported that the right side wing tank contained a quart of fuel and there was some fuel present in the main strainer. No "header tank" had been installed nor were there check valves in the vent system. During the crash sequence, the propeller shaft broke inside the crankcase and the crankshaft could not be rotated. Due to the severity of the break-up of the structure and compromise of the fuel system, the source of the fuel leak could not be determined. The pilot reported that approximately 36 gallons of fuel was on board at the time of departure.