The Nakajima Sakae (栄, Prosperity) was a two-row, 14-cylinder air-cooled radial engine used in a number of combat aircraft of the Imperial Japanese Navy and Imperial Japanese Army before and during World War II.
Design and development
The engine was designed by Nakajima Aircraft Company with code name NAM, as a scaled-down and advanced version of the previous NAL design (Army Type 97 850 hp radial engine, Nakajima Ha5). The Imperial Japanese Army Air Force called the first of the series the Ha-25 (ハ25) and later versions were designated Ha35, Ha105 and Ha115, while the Imperial Japanese Navy Air Service designation was Nakajima NK1, with sub-types identified by Model numbers; thus Nakajima NK1 Sakae 10, 20 and 30 series.
A total of 21,166 were made by Nakajima; 9,067 were manufactured by other firms.
Army Type 99 975 hp Air-cooled RadialLong Army designation for the Nakajima NK1 radial engine named Sakae.
Nakajima Ha25Short Army designation for the initial production version of the Nakajima NK1 radial engine named Sakae.
Nakajima Ha35Nakajima Ha35 Model 11Nakajima Ha35 Model 12Nakajima Ha35 Model 23 - 1,150 hp (858 kW)
Nakajima Ha105Nakajima Ha115Nakajima Ha115-INakajima Ha115-II
Nakajima NK1NK1C Sakae 12 - 925 hp (690 kW) , 940 hp (701 kW) , 975 hp (727 kW)NK1D Sakae 11 - 970 hp (723 kW) , 985 hp (735 kW)NK1F Sakae 21 - 1,115 hp (831 kW) , 1,130 hp (843 kW)NK1E Sakae 31 - 1,130 hp (843 kW) , boosted to 1,210 hp (902 kW) with water-methanol injection
Kawasaki Ki-45 (prototype)Kawasaki Ki-48Kawasaki Ki-56Mitsubishi A6MMitsubishi C5M2Nakajima B5NNakajima J1NNakajima Ki-43Nakajima Ki-115A small number of original Sakae powerplants are on display in aviation museums, usually mounted into the airframes of restored Mitsubishi A6M Zeros - only one airworthy Zero worldwide still flies with a restored Sakae powerplant, the Planes of Fame Museum's A6M5 example, bearing tail number "61-120".
Data from TAIC Manual
Type: 14-cylinder air-cooled two-row radial engineBore: 130 mm (5.1 in)Stroke: 150 mm (5.9 in)Displacement: 27.9 L (1,700 in³)Length: 1,600 mm (63 in)Diameter: 1,150 mm (45 in)Dry weight: 590 kg (1,300 lb)Valvetrain: Overhead valveSupercharger: Gear driven, two speed.Fuel system: 2 BBL D.D. Float Carb. automatic mixture and boost control.Fuel type: 92 OctaneCooling system: Air-cooledPower output: 842.64 kW (1130hp) at altitudeSpecific power: 30.2 kW/L (0.66 hp/in³)Compression ratio: 7:1Power-to-weight ratio: 1.428 kW/kg (0.869 hp/lb)
