Photo from Rexbo.co.uk
The most used means of transport in the modern world is the motor vehicle. This fascinating machine is believed to have appeared in the 17th century in China. The first cars invented were powered by steam, today we have engines powered by fossil fuels, electricity, and solar energy, among others.
Making a combustion engine is not so simple. There are several conditions that must be met in order for the propellant to start and remain in operation. But the principles of physics and chemistry involved are not the most difficult to understand. Strictly speaking, the combustion engine works, as the name suggests, with explosions. They occur inside the cylinders and transform liquid fuel into kinetic energy that moves the wheels.
For these explosions to occur, fuel, oxygen and electricity are required. It will ignite the air and fuel vapor accumulated inside the cylinder. This will push the floor down, which, connected to a crankshaft, will move the gearbox and even the wheels.
The most common type of combustion engine has four strokes, the so-called Otto cycle. The steps are Intake, Compression, Ignition and Exhaustion. This cycle occurs with each engine rotation, in fractions of a second. At the intake, the piston descends, sucking air and fuel into the cylinder through the intake valves. Compression pushes the mixture close to the head, as in a syringe with the outlet capped.
The ignition is given by the spark plug, which explodes the mixture and pushes the piston down again, generating movement. In the exhaust, the piston rises again pushing the gases generated by the explosion out of the cylinder through the exhaust valves.
The first turns of the engine, before the “magic” begins, are given by the starter. It drives the engine, while the injection system splashes the first jets of fuel into the intake chamber. When the first explosion occurs, the engine “starts” and the entire cycle begins.
Therefore, if the battery is low, the starter system may not be strong enough to rotate all moving parts of the engine alone. This makes the start “heavier”, or even impossible.
With the engine running, it is the alternator that maintains the voltage required for spark plugs to occur. If the part is also compromised, the engine will “die”, since the spark will be weak or non-existent, insufficient to maintain the ignition cycle. It also powers all of the car’s electrical systems, from lights to steering with electrical assistance, for example. It is a small power plant, also capable of recharging the battery – used at startup.