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Nakajima Homare 12, Ha 45 Model 12, 2-Row, Radial 18 Engine

Air and Space Museum

Object Details

Manufacturer

Nakajima Hikoki K. K.

Physical Description

Type: Reciprocating, 18 cylinders, 2-rows, radial, air cooled
Power rating: 1,339 kW (1,795 hp) at 2,900 rpm
Displacement: 35.9 L (2,195 cu in.)
Bore and Stroke: 130 mm (5.1 in.) x 150 mm (5.9 in.)
Weight: Unknown

Summary

The Homare (Honor) was Japan’s most-used engine in the latter years of World War II. It had a very high specific output, incorporating for the first time in a Japanese engine, a steel crankcase, dynamic balancers, a dual magneto with a remote distributor (on the nose), and a nose sump pump. Its supercharger drive followed a Wright design, with a planetary reduction gear in series with the high gear for obtaining a lower compression ratio. All models suffered from unreliability, service difficulty (particularly when first entering service), and vibration.
The artifact powered the Yokusuka P1Y1 Ginga (Milky Way) (Allied Code Name FRANCES) twin- engine aircraft for low-altitude torpedo and dive-bombing attacks. Several of these aircraft carried out Kamikaze suicide attacks against American warships. This particular NK9C (Ha45-12) engine model also powered the Aichi B7A2 Ryusei (Shooting Star) single engine torpedo bomber (Allied Code Name GRACE), the largest and heaviest Japanese carrier-based aircraft to fly in World War II.

Credit Line

Transferred from the U.S. Air Force

Date

Circa World War II

Inventory Number

A19601985000

Restrictions & Rights

Usage conditions apply

Type

PROPULSION-Reciprocating & Rotary

Materials

Ferrous Alloy
Non-Magnetic MetalWood
Organic Fiber Fabric
Unknown Coating
Paint
Copper Alloy
Possible Asbestos
Adhesive Tape

Dimensions

Other: 3 ft. 10 1/2 in. × 4 ft. 8 in. × 6 ft. 4 in. × 4 ft. 6 in. (118.1 × 142.2 × 193 × 137.2cm)
Approximate (Width and Length of Stand and Height of Engine): 121.9 × 134.6 × 185.4cm (4 ft. × 4 ft. 5 in. × 6 ft. 1 in.)

Country of Origin

Japan

See more items in

National Air and Space Museum Collection

Data Source

National Air and Space Museum

Metadata Usage

Not determined

Link to Original Record

http://n2t.net/ark:/65665/nv9a7186d22-b28c-4805-9676-edd4b07bce8b

Record ID

nasm_A19601985000

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