ASh-21
Type	Radial engine
Manufacturer	Shvetsov OKB-19 in Perm'
First run	1945
Number built	7,636
Developed from	Shvetsov ASh-82

The Shvetsov ASh-21 is a seven-cylinder single-row air-cooled radial aero engine.

The ASh-21 is basically a single-row version of the Shvetsov ASh-82. The ASh-21 also incorporates a number of parts from the ASh-62 radial engine. Design began in 1945, and by 1947 testing had finished and production had begun. Between 1947 and 1955 7,636 ASh-21 engines had been built in the USSR and beginning in 1952 it was produced in Czechoslovakia as the M-21.

• Beriev Be-8
• Beriev Be-30 (prototype)
• Yakovlev Yak-11
• Yakovlev Yak-16

• Type: Seven-cylinder, air-cooled, single-row, radial engine
• Bore: 155.5 mm (6.12 in)
• Stroke: 155 mm (6.10 in)
• Displacement: 20.6 L (1,257 cu in)
• Dry weight: 487 kg (1,074 lb)

• Supercharger: Single stage, single speed, geared centrifugal supercharger
• Fuel system: Carburetor
• Cooling system: Air

• Power output:
  
• 520 kW (700 hp) at 2,300 rpm takeoff power
• 459 kW (615 hp) at 1,700 m (5,580 ft)
• Specific power: 25.5 kW/L (0.56 hp/in³)
• Compression ratio: 6.4:1
• Power-to-weight ratio: 1.07 kW/kg (0.65 hp/lb)

Comparable engines

• Wright R-1300 Cyclone 7

Related lists

• List of aircraft engines

• Gunston, Bill (1986). World Encyclopedia of Aero Engines. Wellingborough: Patrick Stephens. p. 175.
• Kotelnikov, Vladimir (2005). Russian Piston Aero Engines. Crowood Press Ltd. pp. 118–119.