The main function of the engine is to transform fuel into energy capable of generating movement in the wheels. The heart of this system is a small combustion chamber called a cylinder. Inside each cylinder – passenger cars usually have four or six – are the pistons. The burning of fuel makes the pistons move, turning an axis called crankshaft, which will take the mechanical energy to the transmission system, which in turn distributes this energy to the wheels. The result of this chain reaction is the movement of the car. Other components help the movement not stop. The battery generates the electrical current that makes the fuel explode. Before reaching the engine, this current is amplified by the coil and passes through the distributor, which divides the current between the engine spark plugs. There are also two filters – the oil filter, which purifies the engine’s lubricating liquid, and the air filter, which stops impurities from the air that the car throws at the pistons. Finally, the radiator uses water from the reservoir to cool the engine, keeping the temperature controlled. How these parts fit together and make the car go, you can see on the side
Key acronyms for engine
CYLINDER (DC)
Volume of air and fuel that the cylinders can hold. If a car has four cylinders with a capacity of 0.25 liters of air and fuel each, the displacement will be 1 liter (0.25 X 4 = 1). In this case, we say that the engine is 1.0 or has 1000 cc
RPM’s per minute (RPM)
Number of revolutions per minute of the crankshaft. Generally, a passenger car reaches up to 6 000 rpm
POWER (CV)
Calculation involving displacement, rpm and engine and fuel efficiency. A 1.0 car turning at 6000 rpm has a power of 65 hp (horsepower)
Explosion of air and fuel inside the cylinders is the force that makes the car go
1. Imagine that your vehicle is stopped and you turn the key in the ignition. When this rolls over, the battery sends electricity to the starter, an electric motor that is turned on to make the pistons in the cylinder move for the first time. From there, the engine is on
2. For the engine to keep moving, the pistons need fuel, which is injected into the cylinders through the injection nozzles. Another piece of equipment, the electronic injection unit, is the “brain” that controls the amount of air and fuel thrown into the engine.
3. The combustion process needs air. It enters the car through the air filter, which stops impurities, and goes to the cylinder, allowing the explosion. The air/fuel ratio has to be exact: with too much air, the engine loses performance. With less air, the consumption of the car increases
4. In each cylinder, the fuel explosion goes like this: first, the air/fuel mixture enters, when the intake valve is open. Then the piston moves upwards, compressing the air/fuel mixture. At that time, the spark plug receives electricity from the battery and generates a spark, causing the air/fuel mixture to explode.
5. The explosion generates a hot gas that expands, pushing the piston down. This “push” makes the piston move the crankshaft, a shaft that receives energy from all the pistons and transforms it into rotation. At the end, the cylinder exhaust valve opens and the combustion gases are released into the exhaust.
6. Crankshaft movement influences other parts. First, through the toothed belt, the rotations are transmitted to a pulley that controls the valves. If the belt breaks, the valves stop working. The in-and-out of fuel and air does not roll and the car breaks down
7. Then, the rotation of the crankshaft is transmitted to the gearbox, a set of gears that transmits the energy of the explosion from the pistons to the wheels, making the car go. Every minute, this whole process is repeated up to 6,000 times in the car’s engine.