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Nakajima provided Japan with its first large radials by building licensed Bristols beginning in the late 1920s, and Gnome-Rhone engines beginning in 1936. Nakajima built three 14-cylinder radial engines. The pre-World War II Mamoru possibly shares characteristics with the Pratt & Whitney R-2000. It was the most powerful 14-cylinder engine ever built, with versions at 1,790 kW (2,400 hp) and one of the largest at 44.49 L (2,715 cu. in.).

This engine is of the type that powered the World War II Japanese Nakajima B6N Navy Carrier Attack Bomber Tenzan Type 11 (Allied Code Name Jill). Between 1941 and 1944, 200 engines of all Mamoru series were manufactured, but these were generally not considered successful. After 1945, the company became Fuji, building airframes only.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date Circa World War II Country of Origin Japan Type PROPULSION-Reciprocating & Rotary Manufacturer Nakajima Hikoki K. K.
 Physical Description Type: Reciprocating, 14 cylinders, 2 rows, radial, air-cooled Power rating: 1,394 kW (1,870 hp) at 2,600 rpm Displacement: 44.49 L (2,715 cu. in.) Bore and Stroke: 155 mm (6.1 in.) x 170 mm (6.69 in.) Weight: Not available Manufactured circa World War II Has baffles; missing data plate; some cooling fins bent Dimensions Approximate: 162.56 x 226.06 x 167.64cm (5ft 4in. x 7ft 5in. x 5ft 6in.)
3-D (Weight on stand): 1230.2kg (2712lb.)
 Materials Aluminum, Steel, Rubber, Copper, Ceramic, Magnesium, Wood
 Inventory Number A19710933000 Credit Line Transferred from the U.S. Navy Data Source National Air and Space Museum Restrictions & Rights Open Access (CCO)
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