Our car is something that many of us take for granted on a daily basis unless something goes wrong. You get in, put the key in, start the engine, and start out to your destination without any thought as to the complex processes that are going on underneath the hood to make this happen. Understanding how your car engine works give us a better understanding of how to take care of it and keep it maintained. It will also help you understand your mechanic when something goes wrong. Now, let’s delve into the basics of your car.
Car Engine Basics
If you have been vehicle shopping lately, you might have run across different terms and types. You might wonder what the difference is between an inline, v-cylinder, or boxer motor. You also might wonder how a hybrid or electric motor works and how it is different from a gasoline motor.
All of these questions are things that will help you understand the terminology that is used when you are searching for a vehicle. All combustion motors have certain things in common, and the other terminology only refers to how these different components are assembled and configured. First, let’s explore some basics that apply to all combustion engines, regardless of the specific type.
Internal Combustion Engine
The internal combustion engine is the heart and soul of the vehicle. The basic principle is that it uses the heat produced from the combustion of a fuel source to put force on some component of the motor and move it. When the fuel burns, it creates heat and gases that put pressure on the piston, turbine, blades, or rotor to move these parts over a distance. The process converts chemical energy contained in the fuel into useful work and makes the vehicle go. This is the basic principle, but let’s get into it a bit deeper.
What Creates Engine Power?
The engine power comes from a systematic process that converts a fuel source, such as gasoline, diesel fuel, ethanol, or biodiesel fuel into energy. This conversion occurs through burning the fuel in an enclosed fuel chamber. These fuels contain an incredible amount of energy that is released in the form of a gas that expands due to heat.
This energy is used to create motion and drive the working components of the vehicle power source. There are thousands of little explosions inside your car engine every minute. This is the core principle behind your car engine. The most common type is a four-stroke, but there are other types available. The four strokes will be explained in greater detail later.
Main Engine Components
Before a discussion of the various types of engines can be explained, it is important to understand what the various components of the vehicle’s power source are and what they do. Let’s start from the beginning and explore the basic parts of the car engine. There are main paths throughout the block for engine oil, fuel, and coolant.
Engine Stroke Cycle
Now that you are familiar with the major parts of the vehicle’s power source, it is time to see how all of this fits together. You might have heard the terms “engine cycle” or “four-stroke engine.” These are terms that describe how the vehicle’s power source actually operates and keeps the car in motion.
The two most common types s are two-stroke engines and four-stroke engines. Two-stroke engines are typically used in small tools such as weed trimmers, lawnmowers, and chainsaws. A car uses a four-stroke engine. There are also five-stroke, and six-stroke engines, but most cars are four-stroke type. The stroke simply refers to the cycle of the vehicle’s power source. Let’s see what happens during each stroke of a four-stroke engine.
1. Intake stroke.
During the intake stroke, the piston moves downward and creates a partial vacuum in the cylinder. This draws in the fuel/air mixture. The mixture enters the piston shaft through the intake valve located at the top of the cylinder. Only a tiny bit of air needs to be mixed with the fuel.
2. Compression stroke.
Once the fuel and air are in the cylinder, the compression stroke compresses this mixture so that the combustion explosion will be more powerful. The piston moves up, compressing the mixture to the top of the cylinder.
3. Combustion stroke.
Once the piston is very close to the top of the cylinder, the spark plug ignites the gas and causes a tiny explosion. The force of this explosion drives the piston down again. This stroke is sometimes called the power stroke because this is where the vehicle’s power source gets its power.
4. Exhaust stroke.
The final stroke is the exhaust stroke. The intake valve opens, and the exhaust leaves the piston shaft and enters into the exhaust system. Now, the piston is at the bottom, ready for the camshaft to allows the next batch of fuel and air into the chamber.
Now, you understand how all of the parts work together to create the motion that powers the car. It is quite a simple process, but there is an exception to this process. A Diesel or Otto cycle type uses a different stroke cycle. If your car has direct injection, then only air enters the piston shaft during the intake stroke.
Different Engine Configurations
Now that you know the basic parts and how they work, you might be wondering what all of those terms used by auto manufacturers mean. From supercharged to turbocharged, these terms sound good, but what do they actually mean. Let’s see if we can take some of the mystery out of these terms.
There are several types of configurations that you might see. You might see the terms, “inline,” “v-cylinder,” or “Boxer” engine when you are shopping for cars. Here are the most common vehicle’s power source configurations that you might encounter. You can identify the type that you have by looking at the layout of the combustion cylinders.
These are the different types of configurations found in most cars today. All of them have advantages and disadvantages. All of them also need different types and frequencies of maintenance, too.
Different Engine Configurations by Air Intake
Now you understand the different combustion cylinder configurations, but what about turbocharged and supercharged? You can classify engines according to the type of air intake system that they have, just as you can classify them according to the number and arrangement of cylinders in the block.
Naturally Aspirated Engines. First, let’s discuss the naturally aspirated engine. With a naturally aspirated engine, the air intake depends only on atmospheric pressure. The air is not forced into the combustion cylinder in any way. Many smaller engines and sports cars use naturally aspirated engines.
Auto manufacturers are now favoring smaller, more fuel-efficient engines. They must comply with tightening environmental regulations, but customers want the power that they are used to, so superchargers and turbochargers are now being added to the car engine to improve power on smaller engines.
Supercharged and Turbocharged. A supercharged or turbocharged engine uses a forced-air system that can increase the oxygen available for combustion. This increases the power output of the vehicle’s power source through more efficient fuel burning. This creates better fuel economy without sacrificing power.
A supercharged vehicle’s power source uses a crankshaft to drive energy and produce power. Superchargers have their own oil system. A supercharger acts as a pump that is driven by the engine crankshaft belt. This means that it will compress the same amount of air every time, regardless of the engine speed. Since a supercharger is always on and is belt-driven, it increases the drag on the vehicle’s power source. This means that it can drop fuel efficiency when cruising or at low speeds.
A turbocharger is not connected to the vehicle’s power source and can get up to 15,000 RPMs. Turbochargers share an oil system with the vehicle’s power source, so keeping the oil changed is important. A turbocharger is driven by exhaust gas, which creates a different output, depending on how fast they are being driven. One of the disadvantages of this type of system is that it does not deliver a boost at lower speeds. A turbocharger does not add much extra when cruising or sitting at an idle, but when you kick it into passing gear, the turbocharger kicks in with extra power.
Another disadvantage of his system is that there is a lag time before the system kicks in. This slow response is one reason why racecars use superchargers more than turbochargers.
As you can see, the type of system that you need depends on the type of driving that you do. If you are concerned about fuel economy and only need the power occasionally, a turbocharger might be the best choice. If you want to avoid the lag that occurs when the turbocharger kicks in, then a supercharger might be best, if you do not mind the extra cost in gasoline. One thing to keep in mind is that more power will also increase wear on parts like the transmission, axles, and other parts of the drive train.
Interference vs. Non-interference Engines. An interference engine has to do with the timing belt. In a non-interference engine, if the timing belt breaks, the car engine will not start. However, if you have an interference engine, the engine could suffer major internal damage if the timing belt breaks.
Interference engines developed out of a need to design smaller engines, yet they get the same amount of power. They have better air intake and high compression in the cylinder. They often have larger valves and smaller combustion chambers. It the timing belt breaks on an interference engine, the pistons and valves can collide and become bent or broken. The way to avoid this is to have your timing belt replaced at the recommended mileage for your vehicle.
Keeping your timing belt in good condition is essential in this type of vehicle. If your car have a problems, an OBD2 scanner can help fix them by determining and understanding the errors, that holds in your car’s ECU onboard memory.
Electric Cars and Hybrids
With gasoline prices fluctuating and a demand for more environmentally friendly options, electric cars and hybrids are becoming more popular. Hybrids have two sources of power, one is gasoline, and the other is electric. The vehicle switches between the two systems, only using gasoline when the electric battery is low. An all-electric vehicle is a bit different and only runs on electricity without the need to fill it up with gasoline at all. Let’s explore these new options in power sources.
Since both all-electric cars and hybrids use an electric power source, we will start with an electric vehicle (EVs). To keep it simple, an EV has no gasoline power source. It uses a big battery that you must plug-in when it gets low, just like your cell phone. It does not emit exhaust and does not contain any liquid fuel. You also do not need components such as a fuel pump, fuel lines, or a fuel tank. However, there are some parts that you need to be aware of on an EV.
How Does an Electric Motor Work?
The next question that you might have is how an electric motor on a vehicle works, compared to the piston and combustion cylinder system of a gasoline vehicle. First off, electric motors work virtually the same, whether it is a small child’s toy that moves across the floor, a car, or a big generator that supplies power to homes.
If you were to look inside any electric motor, you would find a rotor or armature. This is the part that spins. The stator is the portion around the rotor. It holds insulated coils of copper wire. Only in rare cases are other metals used.
When a current is applied to the stator, it generates an electric field. This drives the armature. This happens due to magnetics. You might remember playing with two bar magnets with opposite poles on the ends. You will remember that opposite poles attract each other and like poles push each other away. The electric more uses this principle to spin the rotor and create a circular motion. The end of the motor is then attached to the transmission and causes the rotation to cause the vehicle to move.
You might know that hybrids are known for their fuel efficiency. An all-electric vehicle is rated by the distance that it can go on a single charge. Hybrids have an electric assist and are rated by their gasoline fuel efficiency. Although hybrids are usually listed as MPGe instead of just MPG.
A plug-in hybrid is one that plugs into a charger to store energy in the battery. The idea is that the hybrid will run on electricity for as long as possible. When the battery energy runs out, it will switch to the gasoline engine. All hybrids can run on gasoline, but then they are just a regular gasoline vehicle, and you will not see the gains in fuel efficiency.
Hybrid electrics are a bit different. You do not have to plug them in. The battery is charged through regenerative braking and by the internal combustion engine. Both plug-in hybrids and hybrid electrics have advantages and disadvantages. A hybrid electric car engine can be advantageous where there limited charging stations.
Now, you have a basic understanding of how your vehicle works, whether you have an internal combustion engine, an electric, or a hybrid. Hopefully, when you open up the hood, it will not just look like a jumble of metal parts. This will also give you a better understanding of the terminology used when you are buying a new vehicle or when you have to take your vehicle in for repairs and regular maintenance. Understanding how a vehicle works will also make you understand why it is important to keep up with regular maintenance such as oil changes and regular servicing. We ask a lot out of our car engine, and they will last a long time with just a little bit of regular care and attention.
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