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.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date Circa World War II Country of Origin Japan Type PROPULSION-Reciprocating & Rotary Manufacturer Air Technical Arsenal, Japan
 Designer Hirth-Motoren G.m.b.H.
Hitachi
 Physical Description 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) Dimensions 3-D (Object on stand): 147.3 × 87.6 × 104.1cm (4 ft. 10 in. × 2 ft. 10 1/2 in. × 3 ft. 5 in.)
 Materials Ferrous Alloy
Non-Magnetic Metals
Unknown Coating
Fabric Tape
Plastic
Paint
 Inventory Number A19670115000 Credit Line Transferred from the U.S. Air Force Museum. Data Source National Air and Space Museum Restrictions & Rights Usage conditions apply
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