What are the Advantages and Disadvantages of Wankel Rotary Engine ?

Advantages of Wankel Rotary Engine Over Reciprocating Engine

  1. Wankel rotary engine is smaller in size, lighter in weight, and more compact than reciprocating engines.
  2. It is cheaper and simpler in construction for mass production due to the absence of many working parts like connecting rods, crankshafts, valve mechanisms, etc.
  3. Its balancing is easier because it does not contain any reciprocating parts. Road tests have proved that this engine is practically free of vibrations.
  4. Wankel engine volumetric efficiency is very high, often exceeding 100%.
  5. Its power output per kg of the engine is considerably higher.
  6. The Wankel engine requires a lower running cost than the reciprocating engine.
  7. It does not require overdrive because its speed is very high.

Disadvantages of Wankel Engine

  1. Higher fuel consumption at low-speed ranges and higher oil consumption per B.H.P.
  2. Lower torque speeds.
  3. The braking effect of the engine is far less.
  4. Reduction of speed in the transmission is necessary due to the very high engine speed.
  5. Due to the ignition troubles experienced with ordinary ignition system. Spark plugs need to be changed periodically. However, this has been removed by using transistorized ignition.
  6. The main obstacle in the development of the Wankel rotary engine was the sealing problem, which has largely been solved.
  7. Cylinder distortion may occur due to the close proximity of the inlet and exhaust ports.
  8. Very high exhaust gas temperatures, nearly 1600°F, creates problem in the exhaust manifold and silencer designs.