This Hercules twin-cylinder utility engine was designed by Bob Shores and built by Charles Harty, of Colorado, in the 1990s. Chuck used castings and drawings provided by Bob Shores to complete this small utility engine. It burns gasoline on spark ignition and requires oil in the crankcase for splash lubrication. It measures 3.5 inches wide, 5.5 inches high, 7.3 inches long, and weighs 3 pounds- 14 ounces (base included).