A car engine is usually an internal-combustion engine and there are various types of internal-combustion engines. The various types of internal-combustion engines that power the car are diesel engines and gasoline engines. All types of internal-combustion engine have their advantages and their disadvantages.
The external combustion engine
The old-fashioned steam engines that were used at the turn of the century cars were external combustion engines. These were used to power the older cars as well as railway engines. However, internal-combustion engines are more fuel efficient, and this is the reason that these engines also became extremely popular. Further more an internal-combustion engine is also smaller in size in comparison to the external-combustion engine.
The external-combustion engine relied on the power of steam to drive the cars while the internal-combustion engine relies on gasoline or diesel to run the vehicles.
The internal combustion engine
The internal working of the car engine is actually the working of the internal-combustion engine and relies on what is known as the four-stroke combustion cycle. This is what converts the gasoline in the car into the energy that can be used by the car to power its functions. The four-stroke engine was actually invented by Nikolaus Otto in 1867 and is also known as the Otto cycle. The four-stroke engine is the most common engine that is used in the cars and the four strokes are known as intake, compression, combustion and exhaust strokes.
The following cycle is repeated time and again to provide the energy that the car requires. Inside the engine, there is a chamber, where there is an intake valve, the piston, the compression chamber and the exhaust valve. The piston in the engine is connected to the crankshaft by a connecting rod.
The working of an engine
As the crankshaft starts moving, the piston also starts moving. When this happens, the intake valve of the chamber opens and the piston moves back all the way down to the bottom of the chamber. During this process, known as the intake stroke, gasoline is mixed with air.
After this, the compression stroke happens the piston moves all the way back and compresses the mixture of air and gasoline. When compression happens, it makes the explosion that will power the car more forcefully.
When a combustion stroke happens, the piston moves all the way back to the top, and the spark plug ignites this mixture resulting in the controlled explosion of the gasoline. When this explosion happens, the piston moves all the way down and the final stroke known as the exhaust stroke happens. Now the exhaust valve opens and releases out the exhaust from the engine.
This process will be repeated an innumerable time till the car is running, and the gasoline is present. The linear motion of the piston is converted into the rotational motion by the crankshaft. The crankshaft needs to rotate as it needs to turn the wheels of the car
Other fuels being used
Cars are now being developed that will use hydrogen gas as well as gasoline power. Many hybrid cars are there in the market, however they are still expensive.