Mercedes D.IVa

D.IVa
Mercedes D.IVa at the Deutsches Museum. The prominent black piping is the inlet manifold from the carburetor
Type	Inline piston engine
Manufacturer	Daimler Motoren Gesellschaft (DMG)
First run	1917

Not to be confused with Maybach Mb.IVa.

The Mercedes D.IVa was a six-cylinder, water-cooled, inline engine developed in Germany for use in aircraft and built by Daimler Motoren Gesellschaft (DMG).^[1]

Design and development

The D.IVa replaced the failed Mercedes D.IV inline eight-cylinder engine. The D.IVa was primarily used to power bombers and large reconnaissance aircraft. Unlike most German designs, the D.IVa was relatively advanced, including four valves per cylinder powered by an overhead cam, also used on the earlier two-valve per cylinder D.I through D.IIIa powerplants. Designed specifically to be installed in the fuselage, the engine featured a number of design elements intended to reduce its width. For instance, the carburetor was placed behind the engine, feeding fuel to the cylinders via a long pipe. This had the disadvantage of poor fuel distribution. Two versions of the engine were produced in mirror copies, running in opposite directions.

Applications

AEG G.IV AEG G.V AEG R.I Albatros C.X Albatros C.XII Albatros C.XV Friedrichshafen G.III Friedrichshafen G.IV

Gotha G.III Gotha G.IV Gotha G.V Gotha G.VI Gotha G.VII Linke-Hofmann R.I Linke-Hofmann R.II Rumpler C.IV Zeppelin Staaken R.VI

Specifications (D.IVa)

Data from Jane's.^[2][3]

General characteristics

• Type: 6-cylinder, inline piston engine
• Bore: 160 mm (6.3 in)
• Stroke: 180 mm (7.09 in)
• Displacement: 21.72 L (1,324.92 cu in)
• Dry weight: 1,099 lb

Components

• Fuel system: Twin jet Mercedes carburettor with automatic mixture control
• Oil system: Forced feed to bearings and camshaft
• Reduction gear: Direct drive, left-hand tractor

Performance

• Power output: 252 hp at 1,400 rpm
• Compression ratio: 4.94:1
• Fuel consumption: 125 pints per hour
• Oil consumption: 8.125 pints per hour

See also

Related lists

• List of aircraft engines
  

References

Notes

1. ^ Gunston 1989, p.101.
2. ^ Jane's 1993, p. 299
3. ^ Figures were derived from a British bench test of a captured engine.

Bibliography

• Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
• Jane's Fighting Aircraft of World War I. London. Studio Editions Ltd, 1993. ISBN 1-85170-347-0

External links

• Tests of the Daimler D-IVa engine at a high altitude test bench (October 1, 1920)