NANO

ENGINE 273 MPFI

163

ENGINE

GENERAL DESCRIPTION

The primary job of the cooling system is to maintain

the ideal engine working temperature and avoid over-

heating.

The engine performs best at specific designated

temperature. When the engine is cold, components

wear out faster, and the engine is less efficient and

emits more pollution. So another important job of the

cooling system is to allow the engine to heat up as

quickly as possible, and then to keep the engine at a

ideal constant working temperature.

Inside a engine, fuel is constantly burning. A lot of the

heat from this combustion goes right out the exhaust

system, but some of it soaks into the engine, heating

it up. The engine runs best when its coolant is about

200º F (93º C). At this temperature:

•

The combustion chamber is hot enough to

completely vaporize the fuel, providing better

combustion and reducing emissions.

•

The oil used to lubricate the engine has a lower

viscosity (it is thinner), so the engine parts move

more freely and the engine wastes less power

moving its own components around.

•

Minimize wear and tear of engine parts.

The cooling system circulates a fluid through pipes

and passageways 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 the

exchanger.

The

water pump

sends the fluid into the

engine

block

, where it makes its way through passages in

the engine around the cylinders. Then it returns through

the

cylinder head

of the engine. The

thermostat

located where the fluid leaves the engine. The plumb-

ing around the thermostat sends the fluid back to the

pump directly if the thermostat is closed. If it is open,

the fluid goes through the

radiator

first and then back

to the pump.

There is also a separate circuit for the heating system.

This circuit takes fluid from the cylinder head and

passes it through a heater core and then back to the

pump.

SYSTEM SCHEMATICS

1. Radiator

2. Water Pump

3. Cylinder Block

4. Heater Coil

5.Outlet Elbow

6.Cylinder Head

7.Thermostat