May 172013

A combustion engine is a device that converts chemical energy (in the form of fuel) to useful mechanical energy. Combustion engines can be broadly classified into two types. They are:

  1. External Combustion Engine (EC Engine)
  2. Internal Combustion Engine (IC Engine)

External Combustion Engine (EC Engine):

In an external combustion engine, fuel is burnt externally (in a heat exchanger) to produce heat. This heat is used for inducing useful mechanical motion in the cylinder of the engine.

A very good example of external combustion engine is steam engine.

Steam locomotive uses an external combustion engine

Steam Locomotive

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Internal Combustion Engine (IC Engine):

Here, the fuel is burnt inside the cylinder of the engine. Chemical energy of the fuel is converted to thermal energy and thermal energy is converted to mechanical energy, which moves the piston up and down inside the cylinder. Power from the piston is transmitted to the crankshaft which is ultimately transmitted to the wheels via a transmission system.

Modern automobiles use internal combustion engines for propulsion.

Racing Car Engine – An Example of Internal Combustion Engine

Racing Car Engine

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IC engines can be classified into several types based on several criteria. For a brief introduction and classification of Internal Combustion (IC) engines, click here.

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I am a mechanical engineer with a passion for technical stuff. I am the founder and former editor-in-chief of

  • siva

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