Gas or Gasoline Engines
As the name so is the working—this is the case with almost all types of engines. As diesel engine uses diesel as fuel, likewise, gas or gasoline engine is an engine that uses gasoline as a fuel. However, you should note that gasoline engine is known as a petrol engine in the United Kingdom and some other countries, for, they use the word petrol to refer to gasoline. The principle of working of a gasoline engine is similar to that of a diesel engine, as the combustion of fuel mixed with air produces hot gases inside the cylinder that expand against parts of the engine and cause them to move. If you have heard about the term internal-combustion engines, then this is the reason for their nomenclature. The motion of the engine parts produced by the gases is transferred to the crankshaft to turn the wheels to operate the machine or vehicle. So, this is the basic way in which a gasoline engine turns chemical energy into mechanical work.
The structure of gasoline engines is compact and they are usually light in weight for the power they produce, and this is where the advantage of gasoline engines lie: they can be successfully and very effectively used for vehicles. Gas or gasoline engine is used in almost all automobiles, lawn mowers, motorcycles, motor scooters, snowmobiles, and small tractors that are used all over the world. In today’s world, almost all the vehicles use a reciprocating internal combustion engine.
The reciprocating internal combustion engine allows the burning of fuel in a confined combustion chamber, which uses the rapid rise in temperature and energy of the expanding gases to move the piston of the engine. There are basically four stages in a gasoline reciprocating engine. Understanding all these stages provides a clear picture of the working of the gasoline engine. Let us discuss them in detail:
Stage One: Intake Stroke
In the very first stage, as the name implies, intake of fuel happens. The piston starts at the top and moves down as the intake valve opens to allow mixture of gasoline and air enter into the cylinder.
Stage Two: Compression Stroke
In the second stage, the piston moves back to compress the mixture of gas and air. The intensity of the compression allows the explosion to be powerful and thus make a real action in the mixture.
Stage Three: Combustion Stroke
When the piston reaches its peak position, the spark plug emits a spark, which ignites the compressed gasoline. This starts combustion of the gasoline, whereby gases are produce that drive the piston back again, and thus, producing the motion to the piston. The motion is transmitted to the crankshaft to power the automobile.
Stage Four: Exhaust Stroke
At the end of the third stage, when the gasoline has burnt completely, the piston has reached its bottom, the exhaust valve gets opened and all the harmful gases and exhaust are expelled from the cylinder. These four stages make a complete cycle and the process continues till the vehicle is driven.
However, the power required by bigger vehicles can not be produced in single cylinder, and this is the reason why most vehicles use around 4-8 cylinders. All the pistons are connected to the crankshaft by a part called the connecting rod; and at all the times, one cylinder among them goes through the combustion stage. This is done to keep the vehicle in motion and produce continuous power.
These stages are almost common to the diesel engine, the difference lying only in the quality of the mixture, which uses diesel and air instead of gasoline and air.
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