9.9.
Carburation and Carburettor
Automobile spark-ignition engine uses combustible mixture of gasoline and air. Carburation is the mixing of the gasoline fuel with air to get a combustible mixture. In order to change the liquid gasoline into a combustible mixture atomisation and vaporization of gasoline in air take place. A carburettor mixes the correct amount of fuel into the incoming air to give the engine a combustible charge.
The air-fuel ratio required by an engine depends upon temperature, load and speed of the engine. The carburettors operate under all types of conditions and temperatures. Despite various designs available, all carburettors operate on the same basic principle of pressure differential and incorporate same basic system of passages, ports, jets and pumps. Several additional devices are incorporated in the carburettor to provide better fuel mixture, during the full range of driving conditions including high-altitude driving, to improve driveability, reduce emissions, help in cold-weather starting, and avoid overheating.
