‘Internal Combustion’ Engine:
The fuel engines currently in use in vehicles are called Internal Combustion Engines or ‘ICE’ in English. If it is Tamilized to some extent, it can be referred to as ‘internal combustion engine’. It is called so because a combustion or explosion takes place inside the engine and it runs on the energy obtained from it.
Important parts:
Taking the engine of any vehicle, the most important part is the cylinder. Yes, when referring to any car and bike they also mention how many cylinders it has. Depending on the size of the cylinder, the amount of power and torque available from that engine also increases.
The piston inside the cylinder, the connecting rod to which the piston is connected and finally the crank shaft which is connected to the connecting rod.
Functions of the above parts:
It is within the cylinder and piston that the above combustion or explosion takes place. That event causes the piston to move up and down. That movement will actuate the connecting rod which is attached to the piston. The connecting rod rotates the crankshaft to which it is attached. That rotation is what drives our universe (there are many more steps inside the engine before the wheel of our vehicle spins past this, but basically it’s this process that provides the power for all of those events).
The phenomenon of ‘internal combustion’:
Cylinder and piston. The cylinder has two valves namely Intake Valve and Exhaust Valve. An intake valve is a door that allows fuel to enter the cylinder. The exhaust valve is the door for exhausting the smoke produced after the combustion is complete.
Most of the cars and bikes we use today are of the ‘4 stroke’ type. This means that this internal combustion process requires 4 strokes to complete one cycle.
The cycle starts when the piston inside the cylinder is at the top of the cylinder. At the beginning of the cycle the piston starts to come down the cylinder. Then the fuel enters the cylinder through the intake valve. It’s a stroke.
The piston at the lower end of the second cylinder starts moving up again. During this process the fuel inside the cylinder is under very high pressure. This is the second stroke.
Fuel under high pressure explodes and pushes the piston back down. This is the third stroke.
After the third stroke, the fuel turns into smoke and remains inside the cylinder. The piston at the bottom of the cylinder moves back towards the top of the cylinder. Then the smoke leaves the cylinder through the exhaust valve. This is the fourth stroke.
Again the fuel comes in through the intake valve and the next cycle starts. It is called a 4 stroke engine because the internal combustion takes place in four strokes (in 2 stroke engines these four processes are completed in two strokes).
Difference between Petrol and Diesel Engines:
There is a slight difference in the above process for petrol and diesel engines.
Cars with petrol engines also have a small component called a spark plug. This part is located at the top of the cylinder.
Fuel alone is not sufficient for the internal combustion process to take place as described above. Oxygen is also required. In petrol engines, before the fuel enters the cylinder through the intake valve, it is mixed with sufficient oxygen and sent into the cylinder.
During the second stroke, the spark plug is used to cause combustion or detonation when that oxygen-fuel mixture is pressurized. It is the tiny spark in the spark plug that makes internal combustion possible.
But diesel engines do not have spark plugs. In diesel engines the fuel (diesel) is injected directly into the cylinder through fuel injectors.
In diesel engines only air is drawn into the cylinders without fuel during the first of the above four strokes. In the second stroke the same air is subjected to much higher pressure.
The compression ratio is higher in a diesel engine than in a petrol engine. When the air in the cylinder is under very high pressure, fuel is injected into the cylinder through the fuel injector. That would be enough to cause a fire or explosion.
More cylinders, more power:
This is the basic process of running an engine. In this, the power and value of the cylinder increases according to its size.
The most basic of engines is the single cylinder engine used in our commuter bikes. As the name suggests it uses only one cylinder. Hence, its power will also be less.
3 to 12 cylinders are commonly used in cars. The engine of the Maruti Suzuki Swift which was released a few months back has 3 cylinders.
Cars with 12 cylinder engine means high-end cars from Ferrari and Bugatti. The popular Bugatti Chiron model is powered by a 12-cylinder engine. Bugatti also has a 16-cylinder engine.
