Mercedes D.IV

D.IV
Type	Inline piston engine
Manufacturer	Daimler Motoren Gesellschaft (DMG)
Developed from	Mercedes D.III

The Mercedes D.IV was an eight-cylinder, liquid-cooled inline aircraft engine built by Daimler Motoren Gesellschaft (DMG) and used on a small number of German aircraft during World War I.

The design was based around the pistons of the ubiquitous D.III 6-cylinder design and developed 162 kW (217 hp), making it a Class IV motor under the IdFlieg classification system then in use in Imperial Germany. It also employed reduction gearing. When the reliability of the engine proved disappointing, it was supplanted in production by the unrelated six-cylinder Mercedes D.IVa. Specifically, the long crankshaft used in extending the original straight-six design to a straight-eight proved susceptible to breakage.

• AEG C.V
• AEG G.III
• AEG R.I
• AGO C.II
• AGO C.VIII
• Albatros C.V
• DFW R.I
• Gotha G.II
• LVG C.IV

Data from ^{[citation needed]}

• Type: 8-cylinder water-cooled inline aircraft piston engine
• Bore: 140 mm (5.5 in)
• Stroke: 160 mm (6.3 in)
• Displacement: 19.7 L (1,202.4 in³)
• Length: 1,990 mm (78 in)
• Width: 600 mm (24 in)
• Height: 1,040 mm (41 in)
• Dry weight: 365 kg (800 lb)

• Cooling system: Water-cooled

• Power output: 162 kW (217 hp) at 1,400 rpm

Related lists

• List of aircraft engines

• Kroschel, Gunter and Helmust Stützer. (1977) Die deutschen Militarflugzeuge 1910-1918 Wilhelmshaven: Lohse-Eissing Mittler.

• Düsing, Michael (2022). German & Austro-Hungarian Aero Engines of WWI. Vol. 2. n. p.: Aeronaught Books. ISBN 978-1-953201-52-2.

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