The Twin Wasp Junior engine was utilized on American aircraft in the 1930's and its most famous installation was in the Howard Hughes H-1 Racer that, in 1935 and 1937, set a world airspeed record and a transcontinental speed record across the United States, respectively.

Performance:
Type: 14-cylinder air-cooled two-row radial design engine
Bore: 5.1875 in (131.8 mm)
Stroke: 5.1875 in (131.8 mm)
Displacement: 1,535 in³ (25.2 L)
Power output: 825 hp (615 kW) 0.54 hp/in³ (24.4 kW/L)