Engine, Hitachi Hatsukaze Toku Model 13, (Tsu-11), Inverted In-line 4 Engine

Type: Reciprocating, 4 cylinders, In line, Air cooled

Power rating: 67 kW (90 hp) at 2,320 rpm

Displacement: 3.97 L (242.44 cu in.)

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

Weight: 110 kg (242.5 lb)

This artifact is a reconfigured version of a license built Hirth 504a engine, which was named the Hitachi Hatzukaze 11. With step up gearing in the nose, it became the Hitachi Hatzukaze 13. This engine type is believed to have been utilized by Japan in the World War II Ohka 22 flying bomb as the reciprocating component of a Campini-type jet engine.

Hellmuth Hirth was a famous pre-World War I aviator and an excellent engineer. Hirth-Motoren G.m.b.H. of Stuttgart, Germany, was organized in 1931. During 1935-45, following the development of various engine designs, Hirth introduced its 4-, 6-, and 8-cylinder HM 504, HM 506, and HM 508 series, all inverted air-cooled designs. The most successful of these was the HM 504 which powered the Bucker Bu 131 B, Klemm Kl 35B, and Arado-Kabinenzweisitzers Ar 79. Today Hirth 2 cycle engines power ultralight and other light planes.