The earliest use of the Mitsubishi Kasei was on the Mitsubishi G4M "Betty" in 1939.
Kasei (Mars) was the Imperial Navy designation for this engine. The Imperial Army used the designations Ha-32.
 

models

• Kasei 11: 1,530 hp (1141 kW)
• Kasei 23a: 1,820 hp (1357 kW)

specifications

• 14 cylinder, twin-row, air-cooled, radial piston engine
• Displacement: 42 litres (2,565 cubic inches)
• Bore x stroke: 150 x 170 mm
   

used by

• Mitsubishi J2M Raiden