The valves, lifters, and pushrods are integral within the finned portion of the cylinders giving this model the appearance of a 2-cycle engine. In reality, it is an 8.5 cc four-cycle, side-valve (or flat-head), two-cylinder aircraft engine that burns methanol (methyl alcohol) on glow ignition. The valves are positioned parallel to and behind the cylinder rather than above the cylinder and inside the heads. The engine was made in 1980 by J.C. Harbone, of England. It measures 7”-long, 7”-wide, and 5”-high.