avia.wikisort.org - Engine

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
Designed by	Marcel Violet

Design and development

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

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

• Carmier T.10
• Dart Pup
• Dart Kitten
• Druine D.30 Turbulent
• Farman Moustique
• Jodel D.98 Bébé
• Mignet HM-14 Pou du Ciel
• SFAN II
• Starck AS90 New Look
• Tipsy S

Survivors

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

Specifications (4A-00)

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

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