Walter Sagitta

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Sagitta
Walter Sagitta I-R. C. da 470-550 Cv.jpg
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. With a displacement of 18.4 litres (1,123 cu in), it produced up to 373 kW (550 hp) at 2,500 rpm.[1]

Variants[edit]

Sagitta I-MR
550 hp (410 kW) at 2,500rpm at 2,500 m (8,202 ft) - rated height[2]
Sagitta I-SR
535 hp (399 kW) at 2,500rpm at 3,800 m (12,467 ft) - rated height[2]
Sagitta II R.C.
Fully supercharged, 388 kW (520 hp).[3]

Applications[edit]

Specifications (Sagitta I-SR & I-MR)[edit]

Data from [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) - Direct drive, 385 kg (849 lb) - Geared 2:3

Components

  • Valvetrain: enclosed push-rod operated rockers, two valves per cylinder closed by triple springs
  • Supercharger: 8.7 times crankshaft speed - I-MR. 10.2 times crankshaft speed - I-SR
  • Fuel system: Automatic boost and mixture control by a horizontal carburrettor
  • Fuel type: 85 Octane Aviation Gasoline
  • Oil system: Dry sump, one pressure pump and two scavenge pumps
  • Cooling system: Air-cooled

Performance

  • Power output:
  • Take-off: 460 hp (343 kW) at 2,500 rpm - I-SR, 560 hp (418 kW) at 2,500 rpm - I-MR.
  • Rated power: 535 hp (399 kW) at 2,500 rpm at 3,800 m (12,467 ft) - I-SR, 550 hp (410 kW) at 2,500 rpm at 2,300 m (7,546 ft) - I-MR
  • Maximum power: 540 hp (403 kW) at 2,600 rpm at 4,000 m (13,123 ft) - I-SR, 600 hp (447 kW) at 2,500 rpm at 1,750 m (5,741 ft) - I-MR.
  • 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[edit]

Comparable engines
Related lists

References[edit]

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