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The purpose of the cooling system is to keep the engine at its most efficient operating temperature at all speeds under all driving conditions.As fule is burned in the engine, about one-third of the heat energy in the fuel is converted into power.Another third goes out through the exhaust pipe unused, and the remaining third must be handled by the cooling system.This means that the engine can work effectively only when the heat energy is equally handled so as to keep the engine temperature in balance.
So,the temperature is quite essential for an engine to produce power.No engines can work well without suitable operating temperatures.If the engine runs too hot, it may suffer from pre-ignition,while the air-fule charge is ignited prematurely from escessive combustion chamber temperature.Viscosity of the oil circulating in an over heating engine is reduced.Hot oil alvarnish and carbon depostis may be drawn into the combustion chamber where it increases HC emission.This also causes poor performance and premature wear, and may even result in engine damage.What's more, the begavior of the metals at excessively high temperature also differs from that at normal temperatures and can produce a condition in which the metal deforms slowly and continuously at a constant stress.If the engine runs too cold, the fuel will not vaporize properly. If liquid fuel reaches the cylinders, it will reduce lubrication by washing the oil from the cylinder walls and diluting the engine oil.This causes a loss of performance, an increase in HC emissions, and premature engine wear. For these reasons, a ooling system of some kind is necessary in any internal combustion ebgine. |
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