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Comparison Between Water-Cooled Engines and Air-Cooled Engines

the drawing of a four-stroke IC engine

The Comparison Between Water-Cooled Engines and Air-Cooled Engines


The production of an engine is generally tedious work because of the numerous stages it has to pass through to ensure there will be no errors during and after the production.

Issues of drawing, clearance, tolerance, properties of materials, load capacity, speed, torque, and the operating temperature, etc. have to be clearly detailed before the designing and production would take place.

When considering why some engines use a water-cooling system and others use an air-cooling system, it goes beyond mere choice taken by the designer, rather it is entirely based on the nature of the engine based on the overall qualities expected from the engine during the designing stage.

Comparison Between Water-Cooled Engines and Air-Cooled Engines
Comparison Between Water-Cooled Engines and Air-Cooled Engines


Most engines using water-cooling are engines meant to carry heavy loads at their shaft, as a result, they do have multiple cylinders and are usually made with iron-based alloy material for strength, durability, power output, and best performance.

However, based on some conditions, another category of engines may also be equipped with radiators for water-cooling purposes.

Meanwhile, the operation of water-cooled engines is usually seen to have the problem of high temperature because of the nature of the load they bear and their entire bodybuilding design.

To control the engine’s high temperature, a water-cooling system is usually introduced into the engine component.

The part of an engine that reveals the water-cooling system is the radiator. The radiator is usually placed at the front of the engine with a fan controlled by a belt positioned at the gap between the engine and the radiator.

The function of the fan is to force air out from the perforated holes in the radiator such that fresh and cool air could go inside the holes. It is a continuous action that does take place whenever the engine is in operation.

Comparison Between Water-Cooled Engines and Air-Cooled Engines
Comparison Between Water-Cooled Engines and Air-Cooled Engines


The radiator as a water-cooling system of an engine is a very important part, such that any defect in it can cause major damage to the engine.

It is usually made with metallic tubes of small cross-sectional areas fitted together such that water can travel from one tube to another along the up and down part until it exits at the last opening.

During the process of the movement, the water which was initially hot when it came out from the engine will be able to become cool before entering into the engine again.

It is a repeated and continuous process that takes place whenever the engine is running.

Comparison Between Water-Cooled Engines and Air-Cooled Engines
Comparison Between Water-Cooled Engines and Air-Cooled Engines


The major problem that is associated with radiators is the blockage of water which occurs whenever one or more of the radiator tubes had been clogged with dirt such that water would not pass through the tube.


On the other hand, air-cooled engines are engines that depend on the atmospheric air temperature for their cooling. They are less energy-generating engines used for domestic and lower-capacity jobs.

A good of engines using air-cool is the petrol generators for domestic light supply, engines of small grinding machines,  and engines of the machine used by vulcanizers in the pumping of tires.

The air-cooled engines’ bodies are usually made with aluminum-based metallic alloy to control their temperature during operations and that is the reason the metal used in the making of the generators is different from that used in the making of the car engines. It is aimed at temperature control.

However, there are special cases where giant engines have to use an air-cooling system and that will be based on the intended use, overall body design, material used in the body making and expected operating temperature, etc.

Image result for free picture of engine

For the air-cooling system, here is the method engine manufacturers use to make it function effectively;

For a multi-cylinder air-cooled engine buried under a bonnet or boot, it must be some form of fan cooling and ducting in order to cool all cylinders evenly.

The cylinders and their heads are heavily finned and each fin is tapered because heat always flows to the thinnest part of a mass of material. The hotter areas near the exhaust ports on the cylinder heads will have bigger fins than elsewhere.

The fan-blown air will be ducted by a metal cowling so that it stays close to the finned areas; usually, airflow will be regulated by a thermostatically controlled flap valve.

During the warm-up, the flap will be closed to restrict the movement of air and permit the engine to reach its operating temperature quickly. Once the air is fully warm, the flap will open and promote more airflow through the cooling fins.

For engines the fan belt drives the fan, it is important that the belt is renewed at the first sign of wear.


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