Maybach Mb.IVa

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Mb.IVa
Maybach Mb IVa.jpg
Type 6-cyl water-cooled in-line piston engine
National origin Germany
Manufacturer Maybach-Motorenbau GmbH
Designed by Karl Maybach
Major applications Zeppelin airships (LZ 105 to 114[1])
Produced 1916 - 1918

The Maybach Mb.IVa (written in German sources as Mb IVa, without a dot) was a six-cylinder inline, water-cooled aircraft and airship engine developed in Germany during World War I by Maybach-Motorenbau GmbH, a subsidiary of Zeppelin. It was one of the world's first series-produced engines designed specifically for high-altitude use. It was quite different engine design than the previous Maybach Mb.IV, not just a simple modification.

Design and development[edit]

Like all engines of that time, the previous Maybach design, the Mb IV, lost at high altitude as much as half of the nominal power of 240 horsepower. The new Maybach Mb IVa of 1916 was the first engine designed to overcome this limitation.[1] It did not use a supercharger, but a much more primitive solution. The engine had purposely "oversized" cylinders, and a significantly higher 6.08:1 compression ratio. It was tested on Wendelstein (mountain)[2] at an altitude of 1800 m and rated there at 245 hp.[3] This would theoretically correspond to rating of about 300 hp at sea level; however, the engine was not designed to withstand such power[4] - it needed to be carefully throttled down at low altitude, so it would not exceed the safe level of 245 hp. It had three carburettor settings, to be changed during the flight depending on the altitude.

The engine has been falsely designated as 260 hp (190 kW) at sea level, so it would not appear inferior to the engines it replaced.[4]

Applications[edit]

During the First World War[edit]

After the First World War[edit]

Other Maybach engines[edit]

The earlier Maybach's engines were:

  • Maybach AZ of 1909: 140 hp (100 kW)[3]
  • Maybach CX of 1915: 210 hp (160 kW)[3]
  • Maybach DW and IR of 1914: 160 hp (120 kW)[3]
  • Maybach HS (there was a variant HSLu, known also as HS-Lu) of 1915: 240 hp (180 kW)[3]
  • Maybach Mb III - a new designation for the existing Maybach IR engine[5]
  • Maybach Mb IV - a new designation for the existing Maybach HS engine[5]

The power ratings for these older engines are at sea level, unlike the rating of the Mb IVa.

Specifications (Mb.IVa)[edit]

Data from Kleinheins.[1]

General characteristics

  • Type: 6-cylinder inline liquid-cooled aircraft engine
  • Bore: 165 mm (6.6 in)
  • Stroke: 180 mm (7.2 in)
  • Displacement: 23.096 l
  • Dry weight: 400 kg (881 lb) (later variant with aluminium pistons 390 kg (859 lb))
  • Designer: Karl Maybach

Components

  • Cooling system: water-cooled

Performance

See also[edit]

Related lists

References[edit]

  1. ^ a b c d Kleinheins, Peter (2005). Die grossen Zeppeline : die Geschichte des Luftschiffbaus (in German). Berlin [u.a.]: Springer. pp. 91–93. ISBN 3-540-21170-5. 
  2. ^ Ernst Heinrich Hirschel; Horst Prem; Gero Madelung (2004). Aeronautical research in Germany : from Lilienthal until today. Berlin: Springer. pp. 217–218. ISBN 3-540-40645-X. 
  3. ^ a b c d e Wilhelm Treue; Stefan Zima; Gustav Burr (1992). Hochleistungsmotoren : Karl Maybach und sein Werk (in German). Düsseldorf: VDI Verlag. p. 290. ISBN 978-3-18-400905-2. 
  4. ^ a b George William Haddow; Peter Michael Grosz (1962). The German giants. Putnam. 
  5. ^ a b Kyrill von Gersdorff; Kurt Grasmann; Karl Prestel; Helmut Schubert (1985). Flugmotoren und Strahltriebwerke : Entwicklungsgeschichte der deutschen Luftfahrtantriebe von den Anfängen bis zu den internationalen Gemeinschaftsentwicklungen (in German) (2. erg. und erw. Aufl. ed.). Koblenz: Bernard & Graefe. p. 26. ISBN 3-7637-5283-8.