Engine, Nakajima Ha 44 Model 12 Ru (Ha 219 Ru), Radial 18

Type: Reciprocating, 18 cylinders, 2 rows, Radial, Air cooled

Power rating: 1,827 kW (2,450 hp) at 2,800 rpm

Displacement: 48.2 L (2,941 cu in.)

Bore and Stroke: 146 mm (5.75 in.) x 160 mm (6.30 in.)

Weight: 1,150 kg (2,535 lb)

Nakajima provided Japan with its first large radials by building Bristols beginning in the late 1920s. In 1936, Nakajima began building Gnome-Rhone engines under license. Its own World War II designs were apparently not considered very good.

With a starboard fuselage exhaust-driven turbo-supercharger and engine-mounted cooling fan, the fuel-injected Nakajima Ha 44 Model 12 powered the Nakajima Ki-87 high-altitude fighter. The government specified performance objectives that were very ambitious, i.e. 800 km/hr (497 mph) with a range of 3,000 km (1,864 miles). These were later revised, but by February 1945, only one prototype aircraft was completed, with turbo-supercharger development problems contributing to the delay. Test flights began in April and, while the aircraft demonstrated good flying characteristics, only five flights were made as difficulties with the engine prevented further testing.

When the war ended, an improved aircraft was on the drawing board, which included a 2,237 kW (3,000 hp) Nakajima Ha-217 engine and belly turbo-supercharger mounting.