The engines are used all over the world for different applications. Engines are most commonly used in different vehicles. According to the cooling method, engines are divided into three types that are air-cooled engines, liquid-cooled engines, and oil-cooled engines. In the previous article, we deeply discussed air-cooled engines. This article mainly explains the oil cooled engine working, parts, and applications.
What is Oil Cooled Engine?
An engine that uses oil as a coolant is known as an oil cooled engine. It is a type of internal combustion engine. There is an oil cooling system that is used to remove the heat from the engine.
As the engine heats up, it transfers heat to the oil, which then usually passes through a heat exchanger, typically a type of radiator known as an oil cooler. The cooled oil flows back into the hot object to cool it continuously.
This engine is basically an air-cooled engine with an external oil cooler. However, some manufacturers term it as an oil-cooled engine to differentiate between the two. The oil-cooled engines are most commonly used in motorcycles.
The benefits of this method are greater than simple air cooling. In addition to being cheaper, it is easier to maintain and technologically simple. The liquid cooling system is not as efficient as the high-performance engine cooling system.
Working of Oil Cooled Engine
The oil-cooled engine works on the thermodynamics principle. The engine oil is taken out of the engine through an oil tube connected to the oil cooler outside the engine.
The oil cooler contains capillary tubes surrounded by metal fins similar to a radiator. These fins provide a larger contact area for better heat dissipation.
As the hot oil passes through the capillary tubes of the oil cooler, it loses its heat to the air passing through the fins of the oil cooler.
The flow of air is achieved due to the forward motion of the vehicle. As the oil loses heat, it becomes cooler and also retains its viscosity.
Read Also: Working of Air-Cooled Engine
Features of Oil Cooled Engine
The oil cooling process helps to improve engine performance. It has longer service intervals and reduced wear and tear of engine components.
The oil-cooled engine is typically used in entry-level performance bikes such as sports bikes, cruisers, and adventure tourers. This engine tends to have lower lube oil consumption due to the effective cooling of oil outside the engine.
What is an Oil-Cooled Engine used for?
Oil cooling is commonly used to cool high-performance motorcycle engines that are not liquid-cooled. Typically, the cylinder barrel remains air-cooled in traditional motorcycle fashion, but the cylinder head benefits from additional cooling. There is already an oil circulation system available for lubrication; this oil is also piped to the cylinder head and used as a liquid coolant.
Compared to an oil system used solely for lubrication, oil cooling requires additional oil capacity, a greater flow rate through the oil pump, and an oil cooler (or a larger cooler than normal).
Suppose air-cooling proves sufficient for much of the running time (such as for an aero-engine in flight or a motorcycle in motion). In that case, oil cooling is an ideal way to cope with those times when extra cooling is needed (such as an aero-engine taxiing before take-off or a motorcycle in a city traffic jam).
But if the engine is a racing engine that always produces huge amounts of heat, water, or liquid, cooling may be preferable.
Read Also: Different Types of Engines
Parts of Oil Cooled Engine
The oil cooled engines have the following major parts:
- Piston
- Connecting rod
- Radiator
- Fins
- Crankshaft
- Camshaft
- Flywheel
Advantages and Disadvantages of Oil-Cooled Engines
Advantages of Oil-Cooled Engine
- The oil-cooled engine has a simple design.
- It has fewer parts.
- Oil has a higher boiling point than water, so it can be used to cool items at a temperature of 100 °C or higher. However, pressurized water cooling may also exceed 100 °C.
- Easy to manufacture and cheaper than liquid-cooled engines.
- Cooling water can be corrosive to the engine and must contain a Corrosion inhibitor/rust inhibitor, whereas oil naturally helps to prevent corrosion.
- Lightweight as compared to liquid-cooled engines.
- Oil is already a lubricant, so no extra coolant tanks, pumps, or radiators are required.
- Lower maintenance compared to liquid-cooled engines.
Disadvantages of Oil-Cooled Engine
- Unlike water, the oil may be flammable.
- These engines are not best for multi-cylinder engines without a fan.
- Pure water may evaporate or boil, but it cannot degrade, although it may become polluted and acidic.
- Engine efficiency gets affected because of variations in speed.
- The specific heat of the water or water/glycol is about twice that of oil, so a given volume of water may absorb more engine heat than the same volume of oil.
- Limited use, such as in bikes.
Oil Cooled Engine Vs Liquid Cooled Engine
The main difference between the oil-cooled engine and the liquid cooled engine is given below:
| Oil Cooled Engine | Liquid Cooled Engine |
|---|---|
| The oil cooled engine uses a particular type of oil for the engine cooling. | The liquid-cooled engine uses a particular fluid such as water to cool the engine. |
| It has less installation cost than the liquid-cooled engine. | It has a high installation cost. |
| These engines have easy construction. | These have complex construction. |
| This engine has a low maintenance cost. | It has a high maintenance cost. |
| It has low efficiency. | The liquid cooled engine is highly efficient. |
| Oil is flammable. Therefore, oil-cooled engines are very hazardous. | These are not much hazardous as oil-cooled engines. |
| It has an easy design. | It has a complex design. |
| It requires less maintenance than the liquid cooled engine. | It requires high maintenance. |
FAQ Section
Which one is better, liquid cooled or oil cooled?
The oil cooled engine has an easy installation and low cost than the liquid-cooled engines. They are easy to construct than liquid cooled engines. However, a liquid cooled engine has high efficiency than oil cooled engines.
Where is Oil Cooler located?
Oil coolers are typically installed on the exterior of the engine and in the automobile front to improve airflow. The oil cooler also connects to the cooling fins, increasing the effective surface area of metal in contact with the air.
The larger the surface area in contact with the cold air, the more heat is dissipated—the higher the airflow rate, the higher the heat dissipation rate.
What is the difference between oil cooled engine and an air-cooled engine?
An air-cooled engine is a type of engine that uses air to cool the engine. It doesn’t contain a radiator. However, an oil-cooled engine is an engine that uses oil to cool the engine. It is basically an advanced version of an air-cooled engine with an external oil cooler.
What are the types of oil coolers?
- Liquid-Cooled oil coolers
- Air-Cooled oil coolers
- Plate-Type oil coolers
- Tube-and-Fin oil coolers
- Radiator-Mounted oil coolers
- Heat Exchanger oil coolers