Guiberson T-1020 Series 4 Radial 9 Diesel Engine

Type: Reciprocating, Diesel, 9 cylinders, radial, Air-cooled

Power rating: 198 kW (265 hp) at 2,250 rpm

Displacement: 16.7 L (1,021 cu in.)

Bore and Stroke: 130 mm (5.125 in.) x 140 mm (5.5 in.)

Weight: 254 kg (559 lb)

The Guiberson Diesel Engine Company was a subsidiary of the Guiberson Corporation of Dallas, Texas which manufactured oil-industry equipment. Work on its first aircraft engine, the A-980, began in 1930. It was test flown in a Waco biplane and certificated in late-1931. The U.S. Navy showed interest in the slightly larger A-918 engine for its low specific fuel consumption; however, diesels developed by the Navy proved too heavy for their power rating and weren't useful as combat engines.

The later A-1020 was similar to its predecessors, but included improved valves. It was test-flown in a Stinson Reliant S.R. 9 aircraft and certificated in 1940 at 231 kW (310 shp). The T-1020 diesel was manufactured during World War II for use in light tanks, and was equipped with a gear-driven fan for cooling. Aircraft use of this engine, cooled by the propeller slipstream, was hampered by the emphasis on tank engine production during the war.