Cooling system engine radiator (cooling system page 4)

Engine Radiator: 

The layout and appearance of a simple type radiator is shown in (the picture). It has two separate circuits- one for the coolant and other for the air. The first one allows the coolant to pass from the top to the bottom tank of the radiator and the latter lets the air to pass through the radiator from the front to the back.

Radiator

Two types of radiator constructions are shown in the picture

Picture:-Two types of radiator

➤ Fan:

Fan

A fan having four or more blades is mounted on the back of the radiator. It is driven by a belt from a pulley on the crankshaft. When it rotates, air is pulled through the radiator and through back toward the engine. It is very necessary to adjust the fan bearing of the dynamo and water pump. Power absorbed will also be excessive. Too slack a belt may affect the efficiency of the cooling system and dynamo output. Moreover a loose belt may slip which results in loss of speed of the water pump, over-heating of the engine and rapid wear of belt.
➤Thermostat:

An engine works poorly when it is completely cold. It uses a lot of fuel, produces less power, and is subject to much more wear than when it is running at its normal temperature as quickly as possible, which means 'turning off' the cooling system. The thermostat serves this purpose. the thermostat is a valve, which opens automatically at a predetermined temperature. It is placed in the radiator pipe leading from the engine to the radiator (In the picture). When the engine is cold the thermostat is closed and the water pump simply pumps water round the cylinder block. When the engine reaches its correct temperature the thermostat opens and water is allowed to circulate thermostat opens and water is allowed to circulate through the radiator to cool the engine.