model number is followed by the suffix 'kai', as in the Shinten Model 21kai, which decodes as the second model of the Shinten engine, 1st revision, specially modified. IJAAS engine naming method The Imperial Japanese Army Air Service referred to its engines by their engine (Japanese:Hatsudoki abbreviated Ha) model number. Ha numbers were assigned in sequence as the engine design was accepted. This engine (Ha6) would be the 6th engine accepted by the IJAAS. Variants Shinten 11 (A7) 920 hp at 2300 rpm (take-off), 700 hp at 2100 rpm (normal). 1934 4 made Shinten 21 (A6) 950 hp at 2320 rpm (take-off), 800 hp at 2150 rpm (normal). Shinten 21kai (A6) 1200 hp at 2360 rpm (take-off), 1020 hp at 2250 rpm (normal). 1934–1939 109 made Applications Mitsubishi Ki-21 Yokosuka H5Y Specifications (Shinten) See also References Notes Bibliography Matsuoka Hisamitsu, Nakanishi Masayoshi. The History of Mitsubishi Aero Engines 1915–1945. Miki Press, Japan, 2005. 1930s aircraft piston engines Aircraft air-cooled radial piston engines Shinten