Béarn 6

Béarn 6D
Type	6-cyl. inverted air-cooled inline piston aircraft engine
National origin	France
Manufacturer	Construction Mécanique du Béarn (CMB)

The Béarn 6 was a six-cylinder air-cooled piston aircraft engine produced in France in the late 1930s, 1940s and early 1950s.^[1]

Design and development[edit]

The Béarn 6 suffered from lack of development and was not a commercial success, most production engines had been removed from service by 1950 due to poor reliability.^{[citation needed]}

Variants[edit]

6C
6D
6D.07

Applications[edit]

Specifications (Béarn 6D)[edit]

Data from Aircraft Engines of the World 1946.^[1]

General characteristics

Type: 6 cylinder, inverted, in-line, four-stroke piston engine
Bore: 130 mm (5.12 in)
Stroke: 135 mm (5.31 in)
Displacement: 10.7 L (653 cu in)
Length: 1,500 mm (59.06 in)
Width: 450 mm (17.72 in)
Height: 825 mm (32.48 in)
Dry weight: 290 kg (640 lb)
Frontal Area: 0.33 m² (3.6 sq ft)

Components

Valvetrain: 2 overhead valves per cylinder, pushrod actuated.
Supercharger: Gear driven single-speed supercharger with 11.15:1 gear ratio.
Fuel system: 1x Zenith 80RGSL-05 updraught carburettor with automatic boost control
Fuel type: 87 octane petrol
Oil system: Pressure fed at 4.8 bar (70 psi), dry sump
Cooling system: Air-cooled
Reduction gear: Planetary reduction gear, 0.67:1 ratio adapted for Ratier or Chauvière variable-pitch propellers
Starter: Air Equipment 51020 electric inertia starter
Ignition: 2 x R.B. GPBA magnetos, 2 x spark plugs per cylinder fed by a shielded ignition harness.

Performance

Power output:
- Take-off: 310 kW (410 hp) at 2,800rpm, 1,160 mm (46 in) / +3.6 kg (7.9 lb) boost with 100/130 octane petrol
- Normal: 260 kW (350 hp) at 2,700rpm at 2,000 m (6,600 ft)
- Cruising: 190 kW (260 hp) at 2,200rpm at 2,000 m (6,600 ft)
Specific power: 27.89 kW/L (0.63 hp/cu.in)
Compression ratio: 7.2:1
Specific fuel consumption: 0.322 kg/(kW h) (0.53 lb/(hp h))
Oil consumption: 0.00669 kg/(kW h)(0.011 lb/(hp h))
Power-to-weight ratio: 0.968 kW/kg (0.585 hp/lb)

References[edit]

^ ^a ^b Wilkinson, Paul H. (1946). Aircraft engines of the World 1946 (3rd ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 220–221.

[Wilkinson1946-1] Wilkinson, Paul H. (1946). Aircraft engines of the World 1946 (3rd ed.). London: Sir Isaac Pitman & Sons Ltd. pp. 220–221.

[1]