Hitachi Hatsukaze 11, Ha 11 Model 11, Inverted In-line 4 Engine

Type: Reciprocating, 4 cylinders, inverted, in-line, air-cooled

Power rating: 82 kW (110 hp) at rpm

Displacement: 3.97 L (242.44 cu in)

Bore and Stroke: 105 mm (4.13 in.) x 115 mm (4.53 in.)

Weight (dry): 116 kg (256 lb)

Note: Description for Hirth HM4/HM-504A.

The Japanese conglomerate Hitachi manufactured aircraft engines from about 1929 until the end of World War II, with a concentration on low-power seven and nine cylinder radials and inverted inline fours. The Hitachi Aircraft Company was formed in 1939 to take over the aircraft and aero-engine branches of the Tokyo Gasu Denki K.K. or Tokyo Gas & Electric Co., Ltd. Many, if not most, Japanese military trainers were powered by Hitachi copies of German designed Hirth air-cooled inline engines.

The Hitachi Hatsukaze powered the Kyushu K9W1 (Allied Code Name Cypress) Navy Type 2 Primary Trainer Model 11, and the similar Army version Kokusai Ki-86, Type 4 Primary Trainer aircraft. The engine was a derivative, licensed copy of the Hirth HM-504A, which powered the Bucker Bu 131 Jungmann aircraft. There were 541 Hatsukaze engines built during World War II between 1941 and 1943.