TIGOR

1.05L REVOTORQ ENGINE 74 Components : A. Radiator : The radiator is a heat exchanger that is used to dis- sipate the coolant heat. A radiator fan is used to create forced air circulation. Radiator consists of radiator core, inlet tank and an outlet tank. Cores are usually made of aluminum. The core has two sets of passages, a set of tubes and a set of fins attached to the tubes. The tubes run from inlet tank to outlet tank. Coolant flows through the tubes and air flows between the fins. The atmospheric air passing between the fins carries away the heat, which lowers the temperature of the coolant. B. Auxiliary Tank : As the engine cools down the system pressure falls down and vacuum is formed. The vacuum valve in radiator cap opens and allows the water from the Auxiliary tank to go back into the radiator. Thus the system does not have any coolant loss during nor- mal operation. C. Thermostat : The thermostat controls the flow of coolant as fol- lows. 1. During a cold start, thermostat does not allow coolant to flow to radiator since it is closed; in- stead the coolant flows through bypass outlet back to the engine .Thus short circuiting of radia- tor which helps in attaining engine working temperature in a very short period. 2. As soon as the coolant temperature reaches the opening temperature of the thermostat, the thermostat valve starts opening gradually and coolant starts flowing to the radiator. At the same time the thermostat by-pass starts closing gradually. 3. As the engine working temperature reaches thermostat full open temperature, the thermostat valve opens fully. In this condition maximum quantity of engine coolant flows from radiator to water pump.