Ever wondered that the car you drive, how does it actually work? What does the engine that you always hear about when a car is mentioned actually does? Well you'll know soon enough!
Basic Parts of a Engine:
A basic piston engine consists of the core of the engine, thee cylinder, with the pistons moving up and down continuously in the cylinders. Cars that have a piston engine consists of 2, 4, 6 and 8 cylinders. In multi cylinder engines, the cylinders are placed in three positions, Inline, V or flat based.
Different configurations have different advantages and disadvantages in terms of smoothness, manufacturing cost and shape characteristics. These advantages and disadvantages make them more suitable for certain vehicles.
The Key parts of an Engine:
-Spark Plugs:
The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly.
-Valves:
The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust. Note that both valves are closed during compression and combustion so that the combustion chamber is sealed.
-Pistons:
A piston is a cylindrical piece of metal that moves up and down inside the cylinder.
-Piston rings:
Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes:
- They prevent the fuel/air mixture and exhaust in the combustion chamber from leaking into the sump during compression and combustion.
- They keep oil in the sump from leaking into the combustion area, where it would be burned and lost.
Most cars that are burning oil are the ones that have busted piston rings and cylinder seals which is usually seen in old cars.
-Connecting Rod:
The connecting rod connects the piston to the crankshaft. It can rotate at both ends so that its angle can change as the piston moves and the crankshaft rotates.
-Crank Shaft:
The crankshaft turns the piston's up and down motion into circular motion just like a crank on a jack-in-the-box does.
-Sump:
The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the sump (the oil pan).
The principle behind any reciprocating internal combustion engine: If you put a tiny amount of high-energy fuel (like gasoline) in a small, enclosed space and ignite it, an incredible amount of energy is released in the form of expanding gas. You can use that energy to propel a potato 500 feet. In this case, the energy is translated into potato motion. You can also use it for more interesting purposes. For example, if you can create a cycle that allows you to set off explosions like this hundreds of times per minute, and if you can harness that energy in a useful way, what you have is the core of a car engine!
Almost all cars currently use what is called a four-stroke combustion cycle to convert gasoline into motion. The four-stroke approach is also known as the Otto cycle, in honor of Nikolaus Otto, who invented it in 1867. The four strokes are:
- Intake stroke
- Compression stroke
- Combustion stroke
- Exhaust stroke
- The piston starts at the top, the intake valve opens, and the piston moves down to let the engine take in a cylinder-full of air and gasoline. This is the intake stroke. Only the tiniest drop of gasoline needs to be mixed into the air for this to work.
- Then the piston moves back up to compress this fuel/air mixture. Compression makes the explosion more powerful.
- When the piston reaches the top of its stroke, the spark plugs emits a spark to ignite the gasoline. The gasoline charge in the cylinder explodes, driving the piston down.
- Once the piston hits the bottom of its stroke, the exhaust valve opens and the exhaust leaves the cylinder to go out the tailpipe.
Now the engine is ready for the next cycle, so it intakes another charge of air and gas.
