The Aichi Ha-70 was a compound engine composed of two 1,700 hp 12-cylinder liquid-cooled inverted V-12

Aichi Atsuta The Aichi AE1A Atsuta (Japanese: or ) was a Japanese licensed version of the German Daimler-Benz DB 601A 12-cylinder liquid-cooled inverted-vee aircraft engine. The Atsuta powered only two models of Imperial Japanese Navy Air Service (IJNAS) air ...

aircraft engines mounted to a common gearbox. The only aircraft powered by the Ha-70 was the

Yokosuka R2Y The Yokosuka R2Y ''Keiun'' (景雲 - "Cirrus Cloud") was a prototype reconnaissance aircraft built in Japan late in World War II. Design and development Commissioned for the Imperial Japanese Navy after the R1Y design was cancelled due to its ...

, an

Imperial Japanese Navy Air Service The was the Naval aviation, air arm of the Imperial Japanese Navy (IJN). The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War. The Japanese military acquired their first air ...

(IJNAS) prototype reconnaissance aircraft that was designed and built near the end 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 vast majority of the world's countries—including all of the great powers—forming two opposin ...

Design and development

In common with Daimler-Benz,

Aichi Kokuki KK was a Japanese aircraft manufacturer which produced several designs for the Imperial Japanese Navy. After the war, the company was reorganized as Aichi Machine Industry Co., Ltd (愛知機械工業) where they made small '' kei'' cars until 1 ...

joined two Aichi Atsuta engines to drive a single propeller through a combining gearbox in very similar fashion to the

Daimler Benz DB 606 The Daimler-Benz DB 601 was a German aircraft engine built during World War II. It was a liquid-cooled inverted V12, and powered the Messerschmitt Bf 109, Messerschmitt Bf 110, and many others. Approximately 19,000 601's were produced befo ...

(two Daimler-Benz DB 601 engines coupled to a gearbox), The

prototype reconnaissance aircraft required a new engine of and after studying the Daimler-Benz DB 606A-2 engine that powered the

Heinkel He 119 The Heinkel He 119 was an experimental single-propeller monoplane with two coupled engines, developed in Germany. A private venture by Heinkel to test radical ideas by the Günter brothers, the He 119 was originally intended to act as an unarmed ...

single-engine reconnaissance bomber, Aichi determined that the required horsepower could be attained by coupling two Atsuta engines with a common gearbox. To obtain the required power the Atsuta would require up-rating by at least horsepower; Aichi continued to improve the Atsuta 32, eventually extracting the required The two inverted Vee Atsuta engines were mounted side-by-side, each rotated outboard from the centre-line so that the inner banks were upright, with sufficient room between them for the exhaust manifolds. The engines were attached to a gearbox that combined the two separate engine drives into a single output shaft.

Daimler-Benz DB 606 The Daimler-Benz DB 601 was a German aircraft engine built during World War II. It was a liquid-cooled inverted V12, and powered the Messerschmitt Bf 109, Messerschmitt Bf 110, and many others. Approximately 19,000 601's were produced befor ...

Application

Fitted to the R2Y the Ha-70 was mounted behind the pilot, requiring a long drive shaft to drive the nose-mounted gear box that mounted the six-bladed propeller.

Specifications

References

Notes

Bibliography

*Monogram Close-Up 13 *R. J. Francillon, Japanese Aircraft of the Pacific War (1970 Putnam & Company) SBN 370 00033 1

External links

* Wilkinson, Stephan (Jan 2003)
With the Noise of a Stone Crusher
, ''Popular Science'' * NASM
Aichi M6A1
{{Aichi aero engines 1940s aircraft piston engines