What is Rear Engine Layout?
In the rear engine layout, the engine sits at the rear of a vehicle. Most of the vehicles use front engine layout because of the effective cooling it offers to run it efficiently. However, due to some design constraints, sometimes engineers use the rear engine layout. This design, i.e. the rear engine layout, places the engine at the rear of the vehicle but behind the rear axle line while the driven wheels are also at the rear of the vehicle.
The rear engine layout is not the most commonly used forms of engine layout. Engineers use it in compact or micro-cars. It places the engine in a location which is accessible from the rear. Thus, being at rear, it does not provide protection to the driver in case of an accident. However, the advantage of rear engine layout is simple design. Placement of the heavy engine closer to the rear wheels makes the drive-train smaller and lighter. It is also simpler and more efficient as it eliminates the need for the propeller shaft while the differential merges with the transmission to save space.
Rear Engine Layout, Rear Wheel Drive:
The longitudinally mounted rear-engine layout places the engine at the farthest rear location and behind the rear axle line. It fits along the vehicle’s length which is parallel to its wheels. The engine attaches to the gear box and drives the rear wheels thru’ a driveshaft as seen in the diagram. Some of the popular cars with longitudinally mounted rear-engine layout with rear wheel drive are Tata Nano and VW Beetle which use similar layout.
Advantages of rear engine layout:
Placing the engine near the rear axle usually results in more weight on the rear axle than the front. This causes uneven weight distribution with rear axle carrying about 65% of the weight. As a result, the all four wheels get even traction under braking. It offers shorter stopping time and braking distance.
Disadvantages of rear engine layout:
However, the disadvantage of rear-engine layout with rear wheel drive is that the car tends to over-steer while slowing down and can become unstable. Furthermore, this layout is inconvenient for liquid-cooled engines because it requires longer coolant pipes in case of front-mounted radiator. It may also require moving the radiator to the sides or rear and addition of air ducts for more airflow to the rear of the car.
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