The Nakajima Homare (誉, "praise" or, more usually, "honour") was an air-cooled twin-row 18 cylinder
radial
Radial is a geometric term of location which may refer to:
Mathematics and Direction
* Vector (geometric), a line
* Radius, adjective form of
* Radial distance, a directional coordinate in a polar coordinate system
* Radial set
* A bearing f ...
Japanese
Japanese may refer to:
* Something from or related to Japan, an island country in East Asia
* Japanese language, spoken mainly in Japan
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** Japanese diaspor ...
aircraft engine manufactured during
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 vast majority of the world's countries—including all of the great powers—forming two opposin ...
.
Producing almost 2,000 horsepower, it was used widely by both 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 Emperor o ...
and 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 ...
. Given the Navy service designation NK9, the "Homare" was also given the company designation NBA, Army experimental designation Ha-45 (ハ45) or, Army long designation Nakajima Army Type 4 1,900 hp Air-Cooled Radial and, (coincidentally) unified designation code of Ha-45.
[Gunston 1989, p.105.]
Design and development
Development of the Homare started in 1940, and certification was completed in 1941. It succeeded Nakajima's previous 14 cylinder
Sakae (Ha-25) engine, which had its own forward seven cylinders staggered from the rear seven for efficient cooling.
The design was exceptionally compact, with an external diameter of 118 cm, a mere 3 cm larger than the Sakae. With a bore and stroke of 130 mm x 150 mm, it was classified as a short-stroke engine. It was designed to output around 1800 hp (1340 kW), or 100 hp (75 kW) per cylinder. However, the tight design of the engine made it difficult to maintain quality in manufacturing, and unreliability in the field was a significant problem; actual output of early models at altitude was in the range of 1300 hp (970 kW), far below the designed capability. Later models had improved performance, and it became one of the predominant powerplants of Japanese military aircraft in the latter part of the war. A total of 9089
were produced.
Variants
* Homare 11 - 1,650 hp (1,230 kW), 1,820 hp (1,357 kW), 1,900 hp (1,417 kW)
* Homare 12 - 1,825 hp (1,361 kW)
* Homare 21 - 1,990 hp (1,460 kW)
* Homare 23 - 2,000 hp (1,491 kW)
* Homare 25 - 2,000 hp (1,491 kW)
* Homare 42 - 2,200 hp (1,640 kW)
Applications
*
Aichi B7A
*
Kawanishi N1K-J
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 ...
*
Mitsubishi A7M
The Mitsubishi A7M ''Reppū'' (烈風, "Strong Wind") was designed as the successor to the Imperial Japanese Navy's A6M Zero, with development beginning in 1942. Performance objectives were to achieve superior speed, climb, diving, and armament o ...
*
Nakajima C6N
The Nakajima C6N ''Saiun'' (彩雲, "Iridescent Cloud") was a carrier-based reconnaissance aircraft used by the Imperial Japanese Navy Air Service in World War II. Advanced for its time, it was the fastest carrier-based aircraft put into service ...
*
Nakajima G8N
The Nakajima G8N ''Renzan'' (連山, "Mountain Range") was a four-engine long-range bomber designed for use by the Imperial Japanese Navy. The Navy designation was "Type 18 land-based attack aircraft" (十八試陸上攻撃機); the Allied code n ...
*
Nakajima J5N
The Nakajima J5N was an abandoned Japanese prototype fighter aircraft of the World War II era.
J5N was developed as twin-engine interceptor for countering attacks by Boeing B-29 Superfortress.
Design and development
During the spring of 1943 ...
*
Nakajima Ki-84
The is a single-seat fighter flown by the Imperial Japanese Army Air Service in the last two years of World War II. The Allied reporting name was "Frank"; the Japanese Army designation was . The Ki-84 is generally considered the best Japanese ...
*
Yokosuka D4Y5
*
Yokosuka P1Y1
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 (Ha-45-21)
See also
References
Notes
Bibliography
*
* ''Jane's Fighting Aircraft of World War II''. London. Studio Editions Ltd, 1998.
* Gunston, Bill. ''World Encyclopaedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989.
{{Imperial Japanese Navy aero engines
Aircraft air-cooled radial piston engines
1940s aircraft piston engines
Nakajima aircraft engines