Mitsubishi Kinsei Explained

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 project; in service, it was known as the MK8 "Kinsei" by the Navy. In 1941 the engine was adopted by Army, receiving designation Ha-112^[1] (later Ha-112-I, 1,300hp Army Type 1). In May 1943 it received Ha-33 unified designation code.

Design and development

Early Kinsei models (1 and 2) had A4 internal designation and their cylinder and detail design was based on the single-row, 9-cylinder air-cooled Pratt and Whitney R-1690 Hornet.^[2]

In 1933 engine underwent a major redesign and redesignated A8. Head layout was reversed to allow exhaust exit to the rear, reducing back-pressure and allowing for a cleaner installation. Compression ratio increased from 5.3:1 to 6.0:1. These changes resulted in a significant performance uplift, compared to previous variants.

Kinsei 41 saw ever further increase in compression ratio from 6.0:1 to 6.6:1, and a larger supercharger. It's also the first variant to receive a two-digit model numbers. 40 series remained in production from 1936 till the end of the war.

Kinsei 50 series saw the final compression ratio increase to 7.0:1. Indirect fuel injection was fitted as well as a larger two-speed supercharger.

Kinsei 60 series was introduction of direct injection and later, a turbo-supercharger. Its development was run parallel to 50 series. Production started in 1940 and lasted till the end of the war.

Variants

Early (A4) variants

Data from Goodwin

Kinsei 1

at 2300 rpm at takeoff

at 2100 rpm at sea level

Kinsei 2

at 2350 rpm at takeoff

at 2100 rpm at

Late (A8) variants

Data from Goodwin

Kinsei 3

at 2150 rpm at

Kinsei 41

at 2500 rpm at

Higher compression ratio, supercharger

Kinsei 42

at 2500 rpm at

Air pump

Kinsei 43

at 2400 rpm at sea level

at 2400 rpm at

De-rated for economy

Model 44

at sea level

Machine gun synchroniser

Kinsei 45

at sea level

Kinsei 46

at sea level

De-rated for extreme economy

Kinsei 51 (MK8A)

at 2500 rpm at

Redesigned cylinder head, added indirect fuel injection, larger two-speed supercharger

Kinsei 52 (MK8B) (Ha-112-I)

at 2500 rpm at

Added water injection

Kinsei 53 (MK8C)

at 2500 rpm at

Higher pressure oil pump

Kinsei 54 (MK8D)

at 2500 rpm at

Added machine gun synchroniser

Model 61 (Ha-112-II)

Added direct fuel injection

Kinsei 62 (MK8P)

at 2600 rpm at

Kinsei 62 Ru (Ha-112-II Ru)

at 2600 rpm at

Ru-102 turbo-supercharger

Applications

References

Book: Goodwin, Mike. Japanese Aero-Engines 1910-1945. 2017. MMPBooks. 2017. 978-83-65281-32-6. Sandomierz, Poland.

Bibliography

Book: Goodwin . Mike . Starkings . Peter . Japanese Aero-Engines 1910-1945 . 2017 . MMPBooks . Sandomierz, Poland. amp . 978-83-65281-32-6.
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.
Peattie, Mark R., Sunburst: The Rise of Japanese Naval Air Power 1909-1941, Annapolis, Maryland: Naval Institute Press, 2001,

Notes and References

Book: Gunston, Bill. World Encyclopaedia of Aero Engines. Patrick Stephens Limited. 1989. 1-85260-163-9. Cambridge, England. 104.
Book: Peattie, Mark R.. Sunburst: The Rise of Japanese Naval Air Power, 1909-1941. Naval Institute Press. 2001. 1-55750-432-6. Annapolis, Maryland. 308.