English: The Atsuta 31 was a licensed version of the Daimler-Benz DB 601A liquid-cooled, inverted V-12 engine. Th 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 carried-based dive bomber and reconnaissance aircraft. Picture taken at the National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Virginia, USA.
- Transferred from the U.S. Navy, Naval Supply Center, Norfolk, Va.
Type: Reciprocating, Inverted V, 12 cylinders, liquid cooled, supercharged, fuel injected
Power rating: 1,044 kW (1,400 hp) at 2,800 rpm
Length: 215.0 cm (84 5/8 in.), Width 71.2 cm (28 1/16 in.), Height: 106.0 cm (41 3/4 in.)
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)
Bearings: Steel backed copper lead
Crankshaft: Ni/Cr Steel
Cylinder blocks: Silicon aluminum alloy
Ignition leads: Fabric covered
Pistons: Similar to 24S aluminum
Propulsion: Reciprocating & Rotary
Country of Origin: Japan
Designer: Daimler-Benz Aktiengesellschaft
Manufacturer: Aichi Aircraft Company (Aichi Kokuki KK)