The was a two-row, 14-cylinder air-cooled

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

built by

Mitsubishi Heavy Industries is a Japanese multinational engineering, electrical equipment and electronics corporation headquartered in Tokyo, Japan. MHI is one of the core companies of the Mitsubishi Group and its automobile division is the predecessor of Mitsubishi ...

and used in a variety of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

ese

aircraft An aircraft is a vehicle that is able to flight, fly by gaining support from the Atmosphere of Earth, air. It counters the force of gravity by using either Buoyancy, static lift or by using the Lift (force), dynamic lift of an airfoil, or in ...

, such as

Mitsubishi J2M The Mitsubishi J2M ''Raiden'' (雷電, "Lightning Bolt") is a single-engined land-based fighter aircraft used by the Imperial Japanese Navy Air Service in World War II. The Allied reporting name was "Jack". Design and development The J2M was d ...

and

Mitsubishi G4M The Mitsubishi G4M was a twin-engine, land-based medium bomber formerly manufactured by the Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and operated by the Imperial Japanese Navy from 1940 to 1945. Its official designat ...

.Gunston 1989, p.104. The Mitsubishi model designation for this engine was A10 while it was an experimental project, in service it was known as the MK4, and known as the Ha101 & Ha111 by the Army and Kasei by the Navy. According to unified designation code it was Ha-32 of the variants from 11 to 27.

Design and development

Although originally ordered by the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

, the ''Kasei'' was based on the earlier Mitsubishi Shinten engine, itself based originally on the

Mitsubishi Kinsei The was a 14-cylinder, air-cooled, twin-row radial aircraft engine developed by Mitsubishi Heavy Industries in Japan in 1934 for the Imperial Japanese Navy. The Mitsubishi model designation for this engine was A8 while it was an experimental ...

. Produced in a wide variety of models, the ''Kasei'' began with a rated

power Power most often refers to: * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power * Power (social and political), the ability to influence people or events ** Abusive power Power may a ...

of , with a gradual evolution to in later wartime versions. Three variants were developed for the Japanese Navy starting in 1939. It was also later adopted by the

Imperial Japanese Army The was the official ground-based armed force of the Empire of Japan from 1868 to 1945. It was controlled by the Imperial Japanese Army General Staff Office and the Ministry of the Army, both of which were nominally subordinate to the Emper ...

as the ''Ha-101'' engine. Unified code was Ha-32. Physically, the engine had a rather large diameter compared to the of the

Nakajima Homare The Nakajima Homare (誉, "praise" or, more usually, "honour") was an air-cooled twin-row 18 cylinder radial Japanese aircraft engine manufactured during World War II. Producing almost 2,000 horsepower, it was used widely by both the Imperial ...

engine. Its size and weight meant it was a challenging engine to use on single engine fighters.

Variants

* MK4A a-3211 :, 2450 rpm at takeoff
, 2350 rpm at
, 2350 rpm at * MK4B a-3212 - same as MK4A 11 * MK4C a-3213 - with extended propeller shaft :, 2450 rpm at takeoff
, 2350 rpm at
, 2350 rpm at * MK4D a-3214 - with contra-rotating shafts * MK4E a-3215 - with improved altitude performance * MK4P a-3221 :, 2600 rpm at takeoff
, 2500 rpm at
, 2500 rpm at * MK4Q a-3222 - same as MK4A 21 * MK4R a-3223 - Water-injection :, 2600 rpm at takeoff
, 2500 rpm at
, 2500 rpm at * MK4R-C a-3223c - - Fitted with a turbo charger that allowed an output of to be maintained up to instead of only * MK4S a-3224 - Same power as the MK4P 21 with contra-rotating shafts * MK4T a-3225 - , * MK4R a-3226 :, 2600 rpm at takeoff
, 2500 rpm at
, 2500 rpm at * MK4U-4 a-3226a - Mechanically driven 3-speed

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced indu ...

: * MK4V a-3227 :

Applications

Kawanishi E15K The Kawanishi E15K ''Shiun'' (紫雲, " Violet Cloud") was a single-engined Japanese reconnaissance floatplane of World War II. The Allied reporting name for the type was "Norm" after Squadron Leader Norman O. Clappison of the RAAF, a member of ...

* Kawanishi H8K *

Kawanishi N1K The Kawanishi N1K ''Kyōfū'' (, "Strong Wind", Allied reporting name "Rex") is an Imperial Japanese Navy floatplane fighter. The Kawanishi N1K-J ''Shiden'' (, "Violet Lightning") was an Imperial Japanese Navy Air Service land-based version o ...

* Mitsubishi Ki-21 *

Nakajima B6N The Nakajima B6N ''Tenzan'' ( ja, 中島 B6N 天山, "Heavenly Mountain", Allied reporting name: "Jill") was the Imperial Japanese Navy's standard carrier-borne torpedo bomber during the final years of World War II and the successor to the B5N ...

* Nakajima G5N *

Yokosuka P1Y The Yokosuka P1Y ''Ginga'' (銀河, "Galaxy") was a twin-engine, land-based bomber developed for the Japanese Imperial Navy in World War II. It was the successor to the Mitsubishi G4M and given the Allied reporting name "Frances". Design and d ...

Specifications (MK4V 27)

References

Notes

Bibliography

* Matsuoka Hisamitsu, Nakanishi Masayoshi. The History of Mitsubishi Aero Engines 1915–1945. Miki Press, Japan, 2005. * * Gunston, Bill. ''World Encyclopaedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * ''Jane's Fighting Aircraft of World War II''. London. Studio Editions Ltd, 1989. * {{Aeroengine-specs Aircraft air-cooled radial piston engines 1930s aircraft piston engines Kasei