This 1/4 scale Cirrus model airplane engine was designed by Merritt Zimmerman and built by Charles Harty, of Colorado, in the 1990s. The scale Cirrus engine measures about 12.5”-long, 9”-high, 4.3”-wide, and weighs 10 pounds. The crankcase, oil pan, front and rear covers were machined from castings; everything else is machined from aluminum, steel, and brass or copper. It burns gasoline on spark ignition and requires oil in the crankcase for splash lubrication.