A car moves forward with the help of an internal combustion system that is either a petrol or a diesel engine. Cars came into being as early as 1885. Karl Benz, a German engineer is the inventor of petrol engine when he attached a gasoline engine on the end of a cart which had three wheels. Hence, it was the first primitive car, which was powered by gas. Nikolaus Otto was, however, more important in this field since he made the proper invention of the gas engine and even the four stroke engine for that matter!
A car is basically a machine which works or moves forward by the process of conversion of energy. It releases the energy which is trapped inside the fuel that is found inside the car and converts it into kinetic energy by moving the gears along with its wheels.
Petroleum is the source of power for any kind of vehicle. Whether it is a plane or car or even the bike that you use, it is petroleum which facilitates the car to convert energy. Petroleum is also called the crude oil. It is a black liquid which is replete with energy which has a thick texture. It was embedded under the surface of the earth and now it is the most important fuel in the world. Petroleum is composed of hydrocarbons. The very nature of these chemicals is that they can produce energy upon combustion.
The chief parts of a car engine:
Car engines, are constructed around a group of cylinders which have the fuels contained in them and let the fuel burn. The cylinders have been mold out of super sturdy metal but they actually close in a similar way like that of the bicycle pumps. They also have pistons which are fitted very tightly which are capable of sliding up and down. The carburetor supplies the fuel and air to the cylinder through the inlet valve. The exhaust gas escapes through the outlet valve. The sparking plug is made with the purpose of setting fire to the fuel. A turning axle or the crankshaft is situated at the end of the cylinder and the piston is attached to the axle.
The mechanism of the four stroke engine to make power:
- Intake: The piston is pulled in a downward direction inside the cylinder with the help of the momentum of the crankshaft. The crankshaft always stays in a state of constant movement, or most of the times. The inlet valve has a blend of air and fuel passing through them and it opens. After the opening of the inlet valve, the mixture of air along with fuel enters the cylinder.
- Compression: After the closure of the inlet valve, the piston again moves in the cylinder in an upward direction. It compresses the mixture which consequently renders it more inflammatory. As soon as the piston comes to the top of the cylinder, the sparking plug starts its actions and fires.
- Power: Ignition of the air-fuel mixture happens by the spark. Hence, a mini explosion takes place. Hot gas is produced as the fuel starts burning within an instant. The piston is again pushed back to down where it was. The fuel has released a lot of energy which is helping to burn the crankshaft now.
- Exhaust: After the opening of the outlet valve, the crankshaft keeps on burning. For a second time, the piston is pushed back in the cylinder in an upward direction. The exhaust gasses that were produced when the fuel was burnt are now forced out of the exhaust outlet.
After these 5 steps, the entire process is repeated again and it keeps on taking place in a cyclical manner.
Cars usually contain 4 cylinders. They are such arranged that they fire with one another out of their steps. It happens thus that, at any given point of time, any one of the cylinders is each one of the steps that we have mentioned above. Some cars even have 12 engines and these cars are particularly very speedy as well as powerful.
Diagnose of The Engine:
Starting from 1990, many engines came to the market controlled by an ECM (Engine control Module), which are a controllers designed to manage the Engines, they generally have inputs and outputs.
The inputs came as signals from sensors like Air temperature, RPM Speed, Engine temperature, The results of consumption of air and gasoline (Oxygen sensor),.. etc
The outputs will be for injectors, sparks, EGR, and other actuators.
Based on a specific program inside this Ecu, it will control these actuators depends on the inputs from these sensors, this will make the engine provide way better efficiency, more power, longer life and easy to maintain.
These Ecus will be diagnosed by diagnostic tools that will connect to the car by OBD socket, usually located inside the car under the steering wheel.
Using such a diagnostic tool will let technician be able to know which sensor or actuator is defected, also these tools are able to program the Ecu and changing the configurations.
BMW was the first factory who adopt this technology in their cars, BMW started using diagnostic tools for their cars in 80s.