How Engine Cooling System Works?

Here you can get Cooling System Working in Engine. Cooling system, apparatus employed to keep the temperature of a structure or device from exceeding limits imposed by needs of safety and efficiency. If overheated, the oil in a mechanical transmission loses its lubricating capacity, while the fluid in a hydraulic coupling or converter leaks under the pressure created.

Engine Cooling System

A vehicle’s engine-cooling system serves not simply to keep the engine cool, but to also keep its temperature heat enough to make sure efficient, easy operation. System additives encompass a radiator to dissipate heat, a fan or fans to ensure adequate airflow for radiator cooling, a thermostat valve that opens when the desired operating temperature is reached and a water pump (or coolant pump) to circulate coolant through the engine, hoses and other components. Most vehicles
now employ an expansion tank that lets in the coolant to expand, and exit, the cooling circuit when hot, and to go back whilst the automobile is turned off and the engine cools.

The cooling system also incorporates elements of the cabin’s ventilation system, because engine warmth is used to heat the automobile’s interior. 

Types of Cooling System

There are two types of cooling systems in cars.

  • Cooled with liquid
  • Cooled with air

one is cooled with liquid and the other is cooled with air. Air-cooled engines are almost a thing of the past, and were a trade mark of older Volkswagen Beetles, as well as the Chevy Corvair.

New motorcycles use air cooling, but, in cars, cooling an engine with air is very rare.  Consequently, for the rest of this article we’ll be dealing solely with liquid cooling systems.

How Does a Car Cooling System Work?

It’s very simple—the cooling system of a automobile cools the engine. But cooling that engine can seem like a gigantic task, especially while one considers how a lot heat a car engine generates.

Think about it.  The engine of a small car traveling at 50 mph on the highway will produce approximately 4000 explosions consistent with minute.  Along with all of the friction of the moving parts, that’s a lot of heat to be concentrated in one place.  Without an effective cooling system, the engine would heat up and quit functioning within a few minutes.

The present day cooling system should maintain the car cool in ambient temperatures of 115 degrees, in addition to maintaining it heat in -25 degree winter weather.

How the coolant circulates


A typical water-cooling system with an engine-driven fan: note the bypass hose starting up warm coolant for the heater. The pressure cap on the expansion tank has a spring-loaded valve which opens above a certain pressure.

A water-cooled cooling system

A water-cooled engine block and cylinder head have interconnected coolant channels running through them. At the top of the cylinder head all of the channels converge to a single outlet. A pump , pushed with the aid of using a pulley and belt from the crankshaft , drives warm coolant out of the engine to the radiator, that is a form of warmth exchanger.

Unwanted heat is passed from the radiator into the air stream, and the cooled liquid then returns to an inlet at the lowest of the block and flows returned into the channels again. Usually the pump sends coolant up through the engine and down through the radiator, taking advantage of the fact that warm water expands, turns into lighter and rises above cool water whilst heated. Its natural tendency is to flow upwards, and the pump assists circulation.

The radiator is related to the engine with the aid of using rubber hoses, and has a top and bottom tank linked with the aid of using a core a bank of many fine tubes. The tubes pass through holes in a stack of thin sheet-metallic fins, so that the middle has a totally huge surface area and can lose warmth rapidly to the cooler air passing through it. On older vehicles the tubes run vertically, but modern, low-fronted automobiles have crossflow radiators with tubes that run from side to side.

In an engine at its everyday running temperature, the coolant is only just below normal boiling point. The risk of boiling is avoided by increasing the pressure in the device, which raises the boiling point. The extra pressure is limited by the radiator cap, which has a pressure valve in it. Excessive pressure opens the valve, and coolant flows out via an overflow pipe. In a cooling system of this kind there may be a continual slight loss of coolant if the engine runs very warm. The system needs topping up from time to time. Later vehicles have a sealed system in which any overflow goes into an expansion tank , from which it is sucked back into the engine when the remaining liquid cools.

Air-cooled engine cooling systems

In an air-cooled engine, the block and cylinder head are made with deep fins on the outside.

Frequently a duct runs all around the fins, and an engine-driven fan blows air through the duct to take heat away from the fins. A temperature-sensitive valve controls the amount of air being pushed around by the fan, and keeps the temperature constant even on cold days.

How the fan helps

The radiator needs a constant flow of air through its core to cool it adequately. When the car is moving, this happens anyway; but when it is stationary a fan is used to help the airflow. The fan may be driven by the engine, but unless the engine is working hard, it is not always needed while the car is moving, so the energy used in driving it wastes fuel .

To overcome this, some cars have a viscous coupling a fluid clutch worked by a temperature sensitive valve that uncouples the fan until the coolant temperature reaches a set point. Other cars have an electric fan, also switched on and off by a temperature sensor. To let the engine warm up quickly, the radiator is closed off by a thermostat , usually sited above the pump. The thermostat has a valve worked by a chamber filled with wax.

When the engine warms up, the wax melts, expands and pushes the valve open, allowing coolant to flow through the radiator. When the engine stops and cools, the valve closes again. Water expands when it freezes, and if the water in an engine freezes it can burst the block or radiator. So antifreeze usually ethylene glycol is added to the water to lower its freezing point to a safe level.

Antifreeze should not be drained each summer; it can normally be left in for two or three years.

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