Junkers L2

L2
Type	4-stroke petrol 6-cylinder water-cooled inline aircraft engine
National origin	Germany
Manufacturer	Junkers Motorenbau GmbH (Jumo)
First run	1925
Number built	58

The Junkers L2 was Junkers' first water-cooled four-stroke engine and the first to be built on a production line, though only 58 were made. It was a six-cylinder inline engine and powered many Junkers aircraft until replaced by the more powerful L5.

Design and development

The Junkers L2 (the L signifying a four-stroke petrol engine rather than a two-stroke diesel) had some features in common with their first petrol engine, the L1, both six-cylinder upright direct drive inline engines with four overhead camshaft driven valves per cylinder, but was water-cooled rather than air-cooled and had a much greater swept volume.^[1] It initially developed a cruise power of 195 horsepower (hp) (145 kW) at 1,550 rpm but was developed to 220 hp (164 kW).^[2]

Operational history

The L2 powered early versions of several Junkers aircraft. It was soon replaced in these models by the more powerful Junkers L5 and only 58 L2s were built.^[1]

Variants

• L2 initial version.
• L2a refined L2, 230 hp.^[1]

Applications

Early versions of^[1]

• Junkers F 13
• Junkers A 20
• Junkers G 23
• Junkers G 24
• Junkers W 33

Re-engined^[3]

• Junkers Ju 21

Specifications (L2)

Data from Kay (2004) pp.263-4

General characteristics

• Type: 6-cylinder upright water-cooled inline 4-stroke piston engine
• Bore: 150 mm (5.906 in)
• Stroke: 180 mm (7.09 in)
• Displacement: 19.1 L (1,166 cu in)
• Length: 1.58 m (5 ft 2¾ in)
• Width: 0.555 m (1 ft 9¾ in)
• Height: 1.085 m (3ft 6¾ in)
• Dry weight: 310 kg (684 lb)

Components

• Valvetrain: Two inlet and two exhaust valves per cylinder, overhead camshaft operated
• Fuel system: Twin carburettors
• Fuel type: Petrol
• Oil system: Combined splash and pressure
• Cooling system: Water-cooled
• Reduction gear: Direct drive

Performance

• Power output: cruise 195 hp (145 kW) at 1,550 rpm, take-off 230 hp (171 kW)
• Fuel consumption: 31.82 kg/h (70.16 lb/hr)

See also

Related lists

• List of aircraft engines

References

1. Kay, Antony (2004). Junkers Aircraft & engines 1913-1945. London: Putnam Aeronautical Books. pp. 263–4. ISBN 0-85177-985-9.
2. Gunston, Bill (1989). World Encyclopaedia of Aero Engines (2 ed.). Wellingborough: Patrick Stephens Ltd. p. 85. ISBN 1-85260-163-9.
3. Kay (2004) Ibid, p. 44