The Ava 4A was a low power flat-four (boxer engine) developed for very light aircraft in France in the 1930s. It was used by several prototypes and at least one production series.

Ava 4A
Type Flat-four, air-cooled two-stroke
National origin France
Manufacturer Ava
Designer Marcel Violet

Design and development

edit

Marcel Violet was a French racing driver who designed his own two-cylinder, two-stroke engines. He also designed a two stroke horizontally opposed flat-four, which was built under licence at L'agence general moteurs "Ava" by Jean Aubry of the Société J. Thibault, G Aubry et Cie, alloy metal specialists, as the Ava 4A.[1][2] It only produced 19 kW (25 hp)[1] and was intended to power small, low cost, single seat aircraft, replacing the aging Anzanis and completing with the French Mengin Type B and the older British Bristol Cherub engines.

The Ava 4A was on display at the November 1936 Paris Salon.[3] It powered several prototypes and also the forty-six examples of the series production variant of the Farman Moustique, the F.451.[4]

Variants

edit
Ava 4A-00
19 kW (25 hp), as described.
Ava 4A-02
Identical to 4A-00 except for 80 mm (3.15 in) bore and increased compression, giving 26 kW (35 hp) continuous power.[1] Weight 38 kg (84 lb).[3]

Applications

edit

Survivors

edit

A 4A-00 survives in a private collection and is sometimes exhibited on loan.[2]


Specifications (4A-00)

edit

Data from Jane's All the World's Aircraft 1938, p.40d[1]

General characteristics

  • Type: Air-cooled flat-four, two-stroke
  • Bore: 70 mm (2.76 in)
  • Stroke: 70 mm (2.76 in)
  • Displacement: 1.08 L (66 cu in)
  • Length: 554 mm (21.81 in) over propeller boss
  • Width: 550 mm (21.65 in)
  • Dry weight: 37 kg (82 lb) including mounting and propeller boss.
  • Opposing cylinders offset. Cast iron cylinders with finned, hemispherical alloy heads. Single piece nitrided steel crankshaft with roller bearings and ball thrust bearing. Light alloy crankcase.

Components

  • Fuel system: Amrac carburettor, rotary inlet distribution valve. One plug per cylinder, two magnetos, each firing two plugs.
  • Fuel type: petroil (4% oil)
  • Cooling system: air

Performance

  • Power output: Continuous 19 kW (25 hp) at 2,300 rpm, maximum 22 kW (30 hp) at 2.500 rpm
  • Specific fuel consumption: 400-440 g/kW (0.66-0.72 lb/hp)

References

edit
  1. ^ a b c d Grey, C.G. (1972). Jane's All the World's Aircraft 1938. London: David & Charles. p. 40d. ISBN 0715 35734 4.
  2. ^ a b "Belgian Aviation Preservation Association". Retrieved 21 February 2017.
  3. ^ a b "Les moteurs Ava". Les Ailes (938): 16. 19 November 1939.
  4. ^ Liron, J.L. (1984). Les avions Farman. Paris: Éditions Larivère. p. 230.