Mitsubishi Ha-43

Ha-43
Type	18-cylinder two-row radial aircraft engine
National origin	Japan
Manufacturer	Mitsubishi Heavy Industries

The Mitsubishi Ha-43, known as the Ha-211 by the Imperial Japanese Army Air Force (IJAAF) and MK9 by the Imperial Japanese Navy Air Service (IJNAS)), was a Japanese 18-cylinder, twin-row air-cooled radial engine developed during World War II. It was a more powerful derivative of Mitsubishi's 14-cylinder Kinsei. While planned for use in several promising aircraft, only prototypes were made and the engine never saw combat.

Design and development

The Ha-43 was Mitsubishi's answer to Nakajima's Ha-45. The engine was planned to produce 2,200 hp (1,600 kW) while retaining high reliability and a superior power-to-weight ratio compared to contemporary engines in its class. The frontal area per hp. was also intended to be the smallest in the world. However, such ambitious targets necessitated extraordinary efforts and ingenuity at the same time.

At the time, Mitsubishi was working to promote a different engine, the Ha-42 (an 18-cylinder derivative of the Kasei), development of which was prioritized above the Ha-43's, delaying its completion. Consequently, the Ha-45 entered service first, albeit plagued with reliability issues, which would also trouble the Ha-43. Numerous promising aircraft, such as the Kyushu J7W interceptor and Mitsubishi's own A7M Reppu fighter, were planned to use the Ha-43, but in the end, such aircraft did not see service before Japan's surrender, nor did the engine itself.

Variants and designations

Data from: Japanese Aero-Engines 1910-1945^[1]

A20: Company designation
Ha-211: IJAAF designation
MK9: IJNAS designation
Ha-43: Unified (IJAAF and IJNAS) designation system

Applications

Specifications (Ha-43/Ha-211/MK9)

Data from Japanese Aero-Engines 1910-1945.^[1]

General characteristics

Type: 18-cylinder air-cooled two-row radial piston engine
Bore: 140 mm (5.5 in.)
Stroke: 150 mm (5.9 in.)
Displacement: 41.7 L (2,546 cu in.)
Length: 2,020 mm (79.5 in.)
Diameter: 1,230 mm (48.4 in.)
Dry weight: 980 kg (2,161 lb)

Components

Supercharger: Centrifugal two-speed mechanical supercharger

Performance

Power output: 1,641 kW (2,200 hp) at 2,900 rpm
Compression ratio: 7.2
boost +350 mm Hg

References

^ ^a ^b Goodwin, Mike; Starkings, Peter (2017). Japanese Aero-Engines 1910-1945. Sandomierz, Poland: MMP Books / Stratus Sp.J. pp. 175–176. ISBN 978-83-65281-32-6.

[Goodwin-1] Goodwin, Mike; Starkings, Peter (2017). Japanese Aero-Engines 1910-1945. Sandomierz, Poland: MMP Books / Stratus Sp.J. pp. 175–176. ISBN 978-83-65281-32-6.

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