en BMW X (engine)

BMW X
	BMW X at the Deutsches Museum Flugwerft Schleissheim
Type	Radial engine
Manufacturer	BMW
First run	1927

The BMW X is a small five-cylinder radial engine for sport and training aircraft. Although this engine proved successful at several large-scale events in 1930, including that year's round-Europe flight, only a few were built.

The successor model to the BMW X five-cylinder radial engine, the BMW Xa, was introduced in 1931, with the swept volume increased from 2.2 L (130 cu in) to 2.9 L (180 cu in). Power output went up from 37 to 51 kW (50 to 68 hp). The Xa was also not built in any quantity and was mainly installed in training and sport aircraft.^[1]

Variants

X: Bore:83 mm (3.3 in), Stroke:80 mm (3.1 in)^[2]
Xa: Bore:90 mm (3.5 in), Stroke:92.5 mm (3.64 in)^[2]

Applications

Specifications (BMW Xa)

Data from Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944,^[3] and Jane's all the World's Aircraft 1931 ^[2]

General characteristics

Type: 5 cylinder radial engine
Bore: 90 mm (3.54 in)
Stroke: 90 mm (3.5 in) / 92.5 mm (3.64 in) (slave rods / master rod)
Displacement: 2.93 L (178.8 cu in) (assumes equal stroke for each cylinder)
Length: 664 mm (26.1 in)
Diameter: 738 mm (29.1 in)
Dry weight: 73 kg (161 lb)

Components

Valvetrain: 1x inlet and exhaust overhead valves per cylinder operated by pushrods and rockers
Fuel system: Sum CFV 36 carburettor
Fuel type: 73 Octane / 80 Octane
Cooling system: Air cooled

Performance

Power output:

68 PS (67 hp; 50 kW) at 2,300 rpm (15 minutes) at sea level
60 PS (59 hp; 44 kW) at 1,590 rpm (30 minutes) at sea level
54 PS (53 hp; 40 kW) at 1,980 rpm (max continuous) at sea level
40 PS (39 hp; 29 kW) at 1,980 rpm (max continuous) at 3,500 m (11,483 ft)

Specific power: 23.2 PS/L (0.375 hp/cu in; 17.1 kW/L)
Compression ratio: 5.7:1
Specific fuel consumption: 0.24 kg/PSh (0.54 lb/(hp⋅h); 0.33 kg/kWh) at max continuous
Oil consumption: 0.005 kg/PSh (0.011 lb/(hp⋅h); 0.0068 kg/kWh) at max continuous
Power-to-weight ratio: 0.74 PS/kg (0.33 hp/lb; 0.54 kW/kg)
B.M.E.P.: 8.4 atm (8.5 bar; 123 psi)

References

^ Gunston, Bill (1989). World encyclopaedia of aero engines (Fully rev. 2nd ed.). P. Stephens. p. 25. ISBN 1-85260-163-9.
^ ^a ^b ^c Grey, C.G., ed. (1931). Jane's all the World's Aircraft 1931. London: Sampson Low, Marston & company, ltd. p. 50d.
^ Schneider, Helmut (Dipl.Ing.) (1944). Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944 (in German) (Facsimile reprint 1986 ed.). Leipzig: Herm. Beyer Verlag. p. 364. ISBN 381120484X.

External links

[Gunston-1] Gunston, Bill (1989). World encyclopaedia of aero engines (Fully rev. 2nd ed.). P. Stephens. p. 25. ISBN 1-85260-163-9.

[JAWA1931-2] Grey, C.G., ed. (1931). Jane's all the World's Aircraft 1931. London: Sampson Low, Marston & company, ltd. p. 50d.

[schneider-3] Schneider, Helmut (Dipl.Ing.) (1944). Flugzeug-Typenbuch. Handbuch der deutschen Luftfahrt- und Zubehör-Industrie 1944 (in German) (Facsimile reprint 1986 ed.). Leipzig: Herm. Beyer Verlag. p. 364. ISBN 381120484X.

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BMW X (engine)