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Walter Sagitta

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Sagitta
Type Piston aero engine
National origin Czechoslovakia
Manufacturer Walter Aircraft Engines
First run 1937

The Walter Sagitta was a Czechoslovakian, air-cooled, inverted V-12 engine that first ran in 1937. This was one of several smaller, low-mass medium power pre-war V-12 engines produced. With a displacement of 18.4 liters (1,123 cu in), it produced up to 373 kW (550 hp) at 2,500 rpm.[1]

Variants

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Sagitta I-MR
410 kW (550 hp) at 2,500rpm at 2,500 m (8,200 ft) - rated height[2]
Sagitta I-SR
400 kW (535 hp) at 2,500rpm at 3,800 m (12,500 ft) - rated height[2]
Sagitta II R.C.
388 kW (520 hp), fully supercharged.[3]
Alfa Romeo 122
Licensed production.

Applications

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Specifications (Sagitta I-MR)

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Left side view

Data from Jane's.[2]

General characteristics

  • Type: 12-cylinder inverted vee piston engine
  • Bore: 118 mm (4.65 in)
  • Stroke: 140 mm (5.51 in)
  • Displacement: 18.372 L (1,121.1 cu in)
  • Length: 1,914 mm (75.35 in)
  • Width: 725 mm (28.54 in)
  • Height: 796 mm (31.34 in)
  • Dry weight: 372 kg (820 lb)

Components

  • Valvetrain: Enclosed push-rod operated rockers, two valves per cylinder closed by triple springs
  • Supercharger: 8.7 times crankshaft speed
  • Fuel system: Automatic boost and mixture control by a horizontal carburettor
  • Fuel type: 85 Octane petrol
  • Oil system: Dry sump, one pressure pump and two scavenge pumps
  • Cooling system: Air-cooled

Performance

  • Power output:
    • Take-off: 418 kW (560 hp) at 2,500 rpm
    • Rated power: 410 kW (550 hp) at 2,500 rpm at 2,300 m (7,500 ft)
    • Maximum power: 447 kW (600 hp) at 2,500 rpm at 1,750 m (5,740 ft)
  • Specific power: 24.29 kW/L (0.534 hp/(cu in))
  • Compression ratio: 6.25:1
  • Specific fuel consumption: 0.315 - 0.328 kg/(kW h) (0.525 - 0.548 lb/(hp h))
  • Oil consumption: 0.004 - 0.0067 kg/(kW h) (0.0067 - 0.11 lb/(hp h))
  • Power-to-weight ratio: 1.046 kW/kg (0.636 hp/lb)

See also

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Comparable engines

Related lists

References

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Notes
  1. ^ Gunston 1989, p. 174.
  2. ^ a b c Jane's All the World's Aircraft 1938. London: Sampson, Low & Martin company Limited. 1938.
  3. ^ Flight - 14 October 1937, p. 381. Retrieved: 8 November 2012
Bibliography
  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9