INTRODUCTION
The automotive industry, like any other, is a constantly evolving industry, where new technology is being explored and tested, so as to provide better, more desirable results for the average consumer. Over time, cars have changed so greatly that one might be unable to recognize what powered the very first automobiles on earth. Today, it is safe to say that there are well over a billion cars on this planet, which has led to numerous benefits as well as consequences. So many vehicles tread the earth, yet in reality the question arises: How does a car even work?
There is so much more to a vehicle than meets the eye. To the average consumer, they see a chassis sitting on an engine, seats and a radio, a steering wheel and accelerator, and that’s mostly as deep as they care to dive into their primary mode of transportation. In order to break down how exactly a car is able to function, there are so many different segments and parts we would have to take into consideration. Namely, the engine, the chassis/suspension/drivetrain, the exhaust system, and the interior, if you will. Even by mentioning these systems, I would be missing so many important features of the average vehicle. Anyhow, today, I would like to start by explaining the engine component of a car, or as I like to call it, the heart of the car.
MODES OF PROPULSION
Let’s start by establishing that there are a multitude of engines out there. The most common gasoline powered engines are the following internal combustion engines: I4 (Inline 4-Cylinder), V6 (V Shape 6-Cylinder), and the V8 (V Shape 8-Cylinder). The ICE has come so far throughout the past 4 decades, and though emissions standards are rising, it is highly unlikely we will see the demise of petrol-powered engines anytime soon. In today’s society, we are even seeing electric vehicles take over the roads, known for their benevolence towards the environment, and great performance. Then there’s the hybrid engine, which combines the two aforementioned modes of propulsion. Usually, hybrid engines have 4 or less cylinders, making room for the electric motor that’s also in the engine bay.
This next part is going to go deep into the engine, explaining all its parts, and how they all come together to create motion out of nothing. Hang on tight. Okay, let’s put ourselves into close perspective with the engine. Hopping into the vehicle, we hit the “Start/Stop” button, and we hear the engine turn over, and roar to life. The battery is “activated”, if you will, and it sends a signal to the engine to jumpstart a “timing belt”, and after about 1 second, the spark plugs in the engine start firing rapidly, so as to bring the engine to life, to about 1200 RPM to be more specific. Now, all systems are “online”, and the engine is in the process of warming up (very important if you want your car to last as long as possible!), which should anywhere from 30 seconds to a couple of minutes (usually depending on the weather at a given location).
THE 4-STROKE CYCLE
Once the engine is warm and at operating temperature (around 80 degrees Celsius), the car is good to go. Let’s talk about the 4-stroke cycle, and as we go through it, I’ll explain more parts of the internal combustion engine. Every I4, V6, V8 (V10, V12, W16…) engine goes through a process known as the 4-stroke cycle, which is how it converts gasoline into movement. The first stroke is called the “Intake” stroke. In this step, an electronically controlled “camshaft” pushes down the “intake valve” on the cylinder. Fuel is sprayed into the cylinder as air comes through the intake valves. As this air-fuel mixture enters the cylinder, the piston within the cylinder is pushed downwards. As the camshaft rotates, causing the intake valves to close, the second stroke begins. The bottom of the piston is connected to a “crankshaft” via a “connecting rod”. Through momentum of the piston moving downwards, the crankshaft begins to rotate. The second step is called the “Compression” stroke. So, the cylinder is fully closed at this point, and full with the air-fuel mixture. As the crankshaft rotates underneath, the air-fuel mixture has nowhere to go but upwards. The third step of the 4-stroke cycle would be the “Combustion” stroke. Since the piston has compressed the , it is at the optimal pressure to be ignited. An important little part known as a “spark plug” ignites this air-fuel mixture at just the right time (electronically controlled again, just like most of the part in an engine). Now that the mixture has been sparked, a mini explosion takes place, and sends the piston downwards, causing more movement of the crankshaft. Through momentum, the 4th stroke of the cycle begins, the exhaust stroke. Here, the electronically controlled camshaft comes into play again, but this time it opens exhaust valves, located an inch or so away from the intake valves. When these valves open the burnt air-fuel mixture exits the cylinder, and the camshaft closes the valve. Whew, so that was a lot. Guess what? Everything I just went through- that only equates to ONE REVOLUTION PER MINUTE. To put this cycle into greater perspective, when a Lamborghini Aventador SV or a Ferrari 488 is roaring down the road, pushing its peak performance, it can be doing as much as 9,000 to 10,000 RPM. The 4-stroke cycle is a truly magnificent process, but there are a countless amount of mini machines that are in play for everything to continue to function smoothly.
Now, the crankshaft is a very important element, because that’s where all the power of the pistons becomes concentrated. All the pistons in the engine are connected to the crankshaft at some point, which is why the more cylinders a car has, the more power it can make at the crankshaft. Let’s talk horsepower for a second. Often times, when you hear people talking about how much power a car has, they will be talking in regard to the BHP, or brake horsepower (power actually being sent to the wheels, and the power the car is physically running in the end). This number is always going to be less than the true horsepower made by the car, because through the transmission and suspension systems, the car will lose a bit of its crankshaft potential energy to heat energy. Hey, what is horsepower anyways? One horsepower is electrically equivalent to 746 watts, but they didn’t have those kinds of calculations back in the day, when they started taking measurements for cars and creating baseline specifications. I remember reading a story about how the measurement of one horsepower was created by attaching a load of weight to a pony, and having the pony pull out the weight from a well. The value was determined to be 33,000 foot-pounds of work per minute, and after all, that’s what horsepower is: how much work you’re doing over a given time, which in the case of cars, is usually signified by revolutions per minute.
FORCED INDUCTION
Turbos: Short for turbocharger, and a seemingly unreal piece of technology. The turbocharger has become an extremely common application, mainly paired with I4 engines. In V6 and V8 engines, if there’s a turbocharger, you can be sure that it’s a fast, performance vehicle. So what is it? The use of a turbocharger indicates forced induction of air into the cylinder, speeding up the 4-stroke cycle, essentially “boosting” the vehicle. Additionally, turbos may prolong the life of the engine, so as the run is running normally, and they may promote better fuel economy for the car. Talking more specifically about how a turbo works-well, basically this is what happens: when the 4th stroke of the 4-stroke cycle is complete, and the exhaust gases are exiting the cylinder, they are redirected towards the turbocharger, where the exhaust gases start to spin at very high speeds. Then, these gases pass through an intercooler where the hot gasses and cooled, and through more piping, the cold air is put back into the engine, as the cycle continues. So like, magic.
CONCLUSION
All in all, the 4-stroke internal combustion engine is definitely a lot to take in. The engine truly is the heart of the vehicle, because without it, so many other systems would fail, not to mention that you wouldn’t even be able to drive. In today’s exponentially tech-powered society, cars are not being neglected when it comes to automating how things function and run. Computers play a massive role in timing when the spark plugs should fire, when the camshafts should turn over, and the timing belt (also electronically controlled), keeps all these parts in check, and makes sure they are moving in harmony.
I hope you all have become a little more knowledgeable when it comes to the automotive industry. There’s still a lot more to cover, which I will be doing next week, when I cover the exhaust system of a vehicle. I’m looking forward to it, and I hope you are as well! Take care, and see you then.
Excite The Mind 