Rear engine

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Scheme

Rear engine is the designation for the engine arrangement in motor vehicles above or behind the rear axle , instead of at the front for front engines or in front of the rear axle for mid-mounted engines . The rear wheels are always driven, in exceptional cases all four wheels. The connection of the rear engine with the gear unit and the driven rear axle is called rear drive .

Constructive advantages and disadvantages

Škoda Furgonet, a prototype of a rear-engined delivery van

There is no cardan shaft in cars with a rear-engined engine, the vehicle is lighter and cheaper to manufacture. Almost all modern buses have a rear engine. Lower floors and one-man operation are possible in public buses (front engines are in the way of ticket sales) and larger storage spaces in coaches. The driver is less exposed to engine noise. In the case of cars (limousines), on the other hand, the trunk is limited because the steering of the front wheels requires space.

In the case of cars, the choice of engine concept is severely limited due to the space available in the rear. So far, only V-engines with four, six or eight cylinders, boxers with up to six cylinders and in-line engines (installed lengthways or transversely) with up to four cylinders have been implemented, but no in-line engines with five cylinders as in front-engined vehicles. The size is also limited - there have been no rear engines with more than 5.5 liters displacement. Flat engines ( boxer engines ), horizontal in-line engines and engines with a small displacement, also with a turbocharger, are often installed. Rear motors installed lengthways are well suited for all-wheel drive , such as in the Puch Haflinger or Porsche 959 .

In winter, for example on snow, vehicles with a rear engine have traction advantages due to the high axle load share of the driven axle. Rear-wheel drive has disadvantages when cornering with high lateral acceleration values. Rear-wheel drive vehicles tend to oversteer and, in extreme cases, the rear to break away. Shift lever and gearbox are far apart and need a more complex transmission device, often in the form of a remote control shaft . In some cases, this requires additional joints and deflection levers, which can impair the gearshift precision and give the driver an inaccurate gearshift feel. Due to the larger moving mass, the actuation forces are higher during the switching process. Instead of a remote control shaft, modern vehicles also have a cable control or an electromotive actuator.

Examples of rear-engined cars

literature

  • Hans-Hermann Braess, Ulrich Seiffert: Vieweg manual automotive technology. 2nd edition, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Braunschweig / Wiesbaden, 2001, ISBN 3-528-13114-4

Web links

Wiktionary: rear engine  - explanations of meanings, word origins, synonyms, translations