Aichi Atsuta 31, Ha 60 Model 31, V-12 Engine


Display Status:

This object is on display in the Boeing Aviation Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.

Aichi Atsuta 31, Ha 60 Model 31, V-12 Engine

Collection Item Summary:

The Atsuta 31 was a licensed version of the Daimler-Benz DB 601A liquid-cooled, inverted V-12 engine. The Atsuta reduced an aircraft’s frontal area, increasing aerodynamic efficiency. Aichi manufactured 873 Atsuta series engines during World War II.

The Atsuta was the only liquid-cooled engine used operationally by the Japanese naval air force. The Ha 60 Model 31 powered the Aichi M6A1 Seiran, a submarine-borne floatplane bomber, and early versions of the Yokosuka D4Y2 series Suisei carrier-based dive bomber and reconnaissance aircraft.

Collection Item Long Description:



Inventory Number


Physical Description

  • Type: Reciprocating, Inverted V, 12 cylinders, liquid cooled, supercharged, fuel injected
  • Power rating: 1,044 kW (1,400 hp) at 2,800 rpm
  • Displacement: 33.9 L (2,069 cu in)
  • Bore and Stroke: 150 mm (5.91 in.) x 160 mm (6.30 in.)
  • Weight: 715 kg (1,576 lb)

Credit Line

Transferred from the U.S. Navy


Daimler-Benz Aktiengesellschaft

Country of Origin



  • Bearings - Steel backed copper lead
  • Crankshaft - Ni/Cr Steel
  • Cylinder blocks - Silicon aluminum alloy
  • Ignition leads - Fabric covered
  • Pistons - Similar to 24S aluminum


Length 215.0 cm (84 5/8 in.), Width 71.2 cm (28 1/16 in.), Height 106.0 cm (41 3/4 in.)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


PROPULSION-Reciprocating & Rotary