Mercedes D.IV

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

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 classification system then in use in Germany. 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.

Applications (excluding D.IVa variant)

• AEG C.V
• AEG G.III
• AEG R.I
• AGO C.II
• AGO C.VIII
• Albatros C.V
• DFW R.I
• Gotha G.II
• various Riesenflugzeuge (R-planes)

Specifications

General characteristics

• 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 (1,200 in³)
• Length: 1,990 mm (78 in)
• Width: 600 mm (24 in)
• Height: 1,040 mm (41 in)
• Dry weight: 365 kg (800 lb)

Components

• Cooling system: Water-cooled

Performance

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

References

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