Cooling system of IC Engine

There are mainly two types of cooling systems :

1. Air cooled system, and 
2. Water cooled system. 

Air Cooled System 

Air cooled system is generally used in small engines say up to 15-20 kW and in airplane engines. In this system fins or extended surfaces are provided on the cylinder walls, cylinder head, etc. Heat generated due to combustion in the engine cylinder will be conducted to the fins and when the air flows over the fins, heat will be dissipated to air. The amount of heat dissipated to air depends upon : 

• Amount of air flowing through the fins. 
• Fin surface area. 
• The thermal conductivity of metal used for fins. 

Advantages of Air Cooled System-

Radiator/pump is absent hence the system is light. 

(b) In the case of the water cooling system there are leakages, but in this case, there are no leakages. 

(c) Coolant and antifreeze solutions are not required. 

(d) This system can be used in cold climates, where if water is used it may freeze.

Disadvantages of Air Cooled System-

•  Comparatively, it is less efficient. 
•  It is used in airplanes and motorcycle engines where the engines are exposed to air directly.

Water cooling system

In this method, cooling water jackets are provided around the cylinder, cylinder head, valve seats etc. The water when circulated through the jackets, it absorbs the heat of combustion. This hot water will then be cooling in the radiator partially by a fan and partially by the flow developed by the forward motion of the vehicle. The cooled water is again recirculated through the water jackets

Advantage

• Uniform cooling of the cylinder, cylinder head, and valves. 
• Specific fuel consumption of engine improves by using a water cooling system.
• If we employ a water cooling system, the engine need not be provided at the front end of a moving vehicle.
• The engine is less noisy as compared with air-cooled engines, as it has water for damping noise. 

Disadvantages 

• It depends upon the supply of water. 
• The water pump which circulates water absorbs considerable power. 
• If the water cooling system fails then it will result in severe damage of engine. 
• The water cooling system is costlier as it has a number of parts. Also, it requires more maintenance and cares for its parts.