During World War II, the Mitsubishi Army Type 1, Ha 31 Model 21 (Ha 102) powered the Mitsubishi Ki-46-II/II KAI, Army Type 100 command reconnaissance aircraft (Allied Code Name DINAH 2), Kawasaki Ki-45 KAI/b/c/d Army Type 2 two-seat fighter Toryu (Allied Code Name NICK), and MC-20 II transport (Allied Code Name TOPSY). There were 7,852 Ha 102 engines built between 1938 and 1945.

The engine type is a highly developed version of the Japanese Navy Zuisei Model 10 series designed in the mid-1930s. The original Model 11 was rated at 649 kW (870 hp) at 2,540 rpm. Following adoption of the “Unified Type Designation System,” the Army’s version of this model was known as the Ha 31-21. The Model 21 was a major redesign of the Model 15 that included a new reduction gear and two-speed supercharger.

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

1944

Country of Origin

Japan

Type

PROPULSION-Reciprocating & Rotary

Manufacturer

Mitsubishi Jukogyo K. K.

Physical Description

Type: Reciprocating, 14 cylinders, 2-rows, radial, air cooled
Power rating: 805 kW (1,080 hp) at 2,700 rpm
Displacement: 28.0 L (1,710 cu in.)
Bore and Stroke: 140 mm (5.51 in.) x 130 mm (5.12 in.)
Weight: 565 kg (1,244 lb)

Dimensions

Other: 3 ft. 8 1/16 in. × 4 ft. 5 in. × 5 ft. 10 in. × 4 ft. 4 in. (111.9 × 134.6 × 177.8 × 132.1cm)

Materials

Aluminum
Uncharacterized Metals
Phenolic Resin
Adhesive Tape
Unknown Coating
Ceramic

Inventory Number

A19601984000

Credit Line

Transferred from the U.S. Air Force

Data Source

National Air and Space Museum

Restrictions & Rights

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