Typical Cooling System

     There are two types of cooling systems on cars：liquid-cooled and air-cooled.

    Liquid cooling

    The cooling system on liquid-cooled cars circulates a fluid through pipes andpassageways in the engine. As this liquid passes through the hot engine, it absorbs heat，cooling the engine. After the fluid leaves the engine，it passes through a heat exchanger，or radiator, which transfers the heat from the fluid to the air blowing through theexchanger.

    Air cooling

    Some older cars, and very few modern cars，are air-cooled. Instead of circulating fluidthrough the engine，the engine block is covered in aluminum fins that conduct the heataway from the cylinder. A powerful fan forces air over these fins，which cools the engineby transferring the heat to the air.