Lawrance L-3 Radial Engine

Type: Reciprocating, Radial, 3 cylinders, air cooled

Power rating: 48 kW (65 hp) at 2,000 rpm

Displacement: 3.7 L (223 cu in)

Bore and Stroke: 108 mm (4.3 in.) x 133 mm (5.3 in.)

Weight: 66.9 kg (147 lb)

Engineer Charles L. Lawrance began developing air-cooled aircraft engines in 1914, and the Lawrance Aero Engine Corporation soon started to manufacture two-cylinder models on a small scale in New York City. The first of its three-cylinder designs, the Model B, appeared in 1916, followed by a series of three-cylinder radials-the L-2, L-3, L-4, and L-5-shortly after World War I. The L-series was an intermediate step toward Lawrance's milestone designs that culminated in the Wright Whirlwind radial engines of the mid-1920s. However, Lawrance lacked the financial resources to further develop his promising radial designs. But, through pressure from the U.S. Navy, Lawrance’s company was merged with Wright, resulting in one of the most successful American engine manufacturers of the twentieth century.

The U.S. Navy used this Lawrance L-3 to power its ultralight Naval Aircraft Factory SA-1 and Loening M-2 Kitten, which operated from aircraft carriers, battleships, and submarines in the early 1920s.