I C Engine with three cylinder

internal-combustion engine, one in which combustion of the fuel takes place in a confined space, producing expanding gases that are used directly to provide mechanical power. Such engines are classified as reciprocating or rotary, spark ignition or compression ignition, and two-stroke or four-stroke; the most familiar combination, used from automobiles to lawn mowers, is the reciprocating, spark-ignited, four-stroke gasoline engine. Other types of internal-combustion engines include the reaction engine and the gas turbine. Engines are rated by their maximum horsepower, which is usually reached a little below the speed at which undue mechanical stresses are developed.
here we designed a three cylinder reciprocating engine mechanism.
  

you can download the CAD design of engine model

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