How Engine Cooling Systems Prevent Overheating

The Mission of the Engine Cooling System

The mission of the cooling system is to keep temperatures within manageable margins while the engine is running. During combustion, engines generate excessive heat which could damage or melt metal elements and the motor. It also cools other mechanical elements such as automatic gearboxes.

Components Requiring Refrigeration

The engine components that require refrigeration include the cylinder head, cylinder block, pistons, and valves, among others. For all other elements, it is necessary to cool the lubricating oil that reaches high operating temperatures. The primary methods used are air cooling, liquid refrigerant, and oil.

Air Cooling Systems

Air cooling uses air to evacuate the heat generated by the engine. The evacuation is carried out upon contact with air outside the engine parts; heat inside the engine moves to the outside by conduction through its components.

To facilitate heat evacuation, the pieces are made of aluminum alloy. Fins are placed outside the elements to be cooled so that the surface area in contact with air is as large as possible. Cooling systems are classified as direct or forced, depending on whether specific elements are present to force the airflow:

Direct Cooling

Direct cooling is used when the engine is mounted in the open air, with no elements to prevent the collision of the air against the engine while driving the vehicle. The higher the speed, the better the cooling. This method is widely used in motorcycles.

Forced Cooling

Forced cooling is a method in which a fan is used to force the passage of air and thereby provide further cooling, even when the vehicle is stopped. It is used in vehicles where the engine is less exposed to air during displacement.

Coolant Cooling Systems

Coolant cooling is based on the use of a coolant (water and antifreeze) responsible for evacuating the waste heat of combustion and maintaining a constant engine operating temperature. The coolant is passed through holes placed in the motor areas to be cooled, flowing through the cylinders and combustion chambers with direct contact. Then, the coolant in the radiator is cooled by air. The set of pipes in the engine and radiator constitute the cooling system.

System Components

This system includes the following components:

• Water pump
• Radiator
• Thermostat
• Fan
• Expansion tank
• Pipes and channels for heating