How do engines work

Atkinson-cycle engines, for example, change the valve timing to make a more efficient but less powerful engine. Turbocharging and supercharging, grouped together under the forced-induction options, pump additional air into the engine, which increases the available oxygen and thus the amount of fuel that can be burned—resulting in more power when you want it and more efficiency when you don't need the power.

Diesel engines do all this without spark plugs. But no matter the engine, as long as it's of the internal-combustion variety, the basics of how it works remain the same. And now you know them. New Cars. Buyer's Guide. Type keyword s to search. Today's Top Stories. Getty Images. The Best. You may be able to find the same content in another format, or you may be able to find more information, at their web site.

Meguiar's Ultimate Quik Detailer. By repeating the process, it creates energy that powers the car. The gasoline engine is a type of internal combustion engine. The gasoline engine has 4 basic strokes including the intake, compression, combustion, and exhaust. Gasoline gets mixed with air easily, so it can produce combustion with just a little spark. As a result, the gasoline engine has a spark plug to ignite the air and fuel mixture.

Here's how the four strokes of the gasoline engine operate. The intake valve opens and the air and fuel mixture is sucked into the cylinder.

The intake valve closes and the air and fuel mixture is compressed by a piston. In this stage, the air and fuel mixture explodes and the power created by the explosion causes the piston to move down. The operation of a diesel engine is similar to the one of a gasoline engine, but they are slightly different in how they ignite the air and fuel mixture. In gasoline engines, the air and fuel are pre-mixed before being sucked into the cylinder.

On the other hand, diesel engines use fuel injectors to spray fuel into the cylinder. As diesel engines have no spark plug, they need to have higher compression ratios to ensure that the air and fuel mixture is compressed enough to make an ignition.

Electric vehicles don't have an internal combustion engine, but instead, they have an electric motor, as they run on electricity. We're sure you can find lots of info at your library and online! Hi, NaKayla! Thanks for joining the conversation! Hi, Eva! That's a very interesting question! We encourage you to keep researching about race cars! Have fun! Hello, Wonder Friend! We're sorry you didn't like this Wonder! Luckily, there are more than 1, other Wonders you can explore on Wonderopolis!

We hope you visit again soon! Thanks for sharing, Rashmi! Visuals are always helpful! Thanks for pointing out the combustion and explosions are not the the same thing, StingJam!

Combustion is a chemical reaction between a fuel and an oxidant that produces heat, while an explosion is a wave of rapidly expanding gases that are created from reacting materials.

While both processes are part of an internal combustion engine, it is important to understand the difference between the two.

Great question, Maan singh! Maybe you can do more research at your library. Well thank you for telling us how much you enjoyed this Wonder, John! We're glad you visited us today to Wonder about engines. Those are both awesome questions you ask!

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We sent you SMS, for complete subscription please reply. Follow Twitter Instagram Facebook. How does an engine work? What is internal combustion?

What are the four phases of the combustion cycle? Wonder What's Next? Try It Out Have you got your engines revved up? Be sure to explore the following activities with a friend or family member: Do you know the parts of a car? Jump online to check out the Anatomy of an Automobile. Learn more about the parts of a car and what they do.

Can you identify each part on your family vehicle? If you really want to learn more about engines, ask an adult friend or family member to pop the hood on the family car, so you can get a closer look at the engine. Can you believe how many parts there are in a modern engine?

If possible, compare the engine in your family vehicle to another type of engine, such as that found on a lawnmower. With today's modern technology, engines are changing to support multiple fuel sources. What will engines be like when you're old enough to drive? Do you think a hybrid or electric vehicle is in your future? Why or why not?

Did you get it? Test your knowledge. What are you wondering? Wonder Words combustion fuel explosion generate enclosed piston harness propel stroke intake compression exhaust valve muffler tailpipe key hood motion Take the Wonder Word Challenge.

Join the Discussion. Dylan Feb 20, Feb 21, Or perhaps you are buying a new car , and you hear things like "2. In this article, we'll discuss the basic idea behind an engine and then go into detail about how all the pieces fit together, what can go wrong and how to increase performance. The purpose of a gasoline car engine is to convert gasoline into motion so that your car can move.

Currently the easiest way to create motion from gasoline is to burn the gasoline inside an engine. Therefore, a car engine is an internal combustion engine — combustion takes place internally. The principle behind any reciprocating internal combustion engine: If you put a tiny amount of high-energy-density 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 for 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 every car with a gasoline engine uses 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 The four strokes are illustrated in the animation. They are:. The piston is connected to the crankshaft by a connecting rod. As the crankshaft revolves, it has the effect of "resetting the cannon. In an engine, the linear motion of the pistons is converted into rotational motion by the crankshaft. The rotational motion is nice because we plan to turn rotate the car's wheels with it anyway.

Now let's look at all the parts that work together to make this happen, starting with the cylinders. The core of the engine is the cylinder, with the piston moving up and down inside the cylinder. Single cylinder engines are typical of most lawn mowers, but usually cars have more than one cylinder four, six and eight cylinders are common.

In a multi-cylinder engine, the cylinders usually are arranged in one of three ways: inline , V or flat also known as horizontally opposed or boxer , as shown in the figures to the left. So that inline four we mentioned at the beginning is an engine with four cylinders arranged in a line. 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 spark must happen at just the right moment for things to work properly. 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. 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:.

Most cars that "burn oil" and have to have a quart added every 1, miles are burning it because the engine is old and the rings no longer seal things properly. Many modern vehicles use more advance materials for piston rings.

That's one of the reasons why engines last longer and can go longer between oil changes. 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. The crankshaft turns the piston's up-and-down motion into circular motion just like a crank on a jack-in-the-box does. The sump surrounds the crankshaft.

It contains some amount of oil , which collects in the bottom of the sump the oil pan. So you go out one morning and your engine will turn over but it won't start. What could be wrong? Now that you know how an engine works, you can understand the basic things that can keep an engine from running. Three fundamental things can happen: a bad fuel mix, lack of compression or lack of spark. Beyond that, thousands of minor things can create problems, but these are the "big three. Lack of compression: If the charge of air and fuel cannot be compressed properly, the combustion process will not work like it should.

Lack of compression might occur for these reasons:. The most common "hole" in a cylinder occurs where the top of the cylinder holding the valves and spark plug and also known as the cylinder head attaches to the cylinder itself.

Generally, the cylinder and the cylinder head bolt together with a thin gasket pressed between them to ensure a good seal. If the gasket breaks down, small holes develop between the cylinder and the cylinder head, and these holes cause leaks. In a properly running engine, all of these factors are working fine. Perfection is not required to make an engine run, but you'll probably notice when things are less than perfect. As you can see, an engine has a number of systems that help it do its job of converting fuel into motion.

We'll look at the different subsystems used in engines in the next few sections. Most engine subsystems can be implemented using different technologies, and better technologies can improve the performance of the engine. Let's look at all of the different subsystems used in modern engines, beginning with the valve train. The valve train consists of the valves and a mechanism that opens and closes them.

The opening and closing system is called a camshaft. The camshaft has lobes on it that move the valves up and down, as shown in Figure 5. Most modern engines have what are called overhead cams. This means that the camshaft is located above the valves, as shown in Figure 5. The cams on the shaft activate the valves directly or through a very short linkage. Older engines used a camshaft located in the sump near the crankshaft. A timing belt or timing chain links the crankshaft to the camshaft so that the valves are in sync with the pistons.

The camshaft is geared to turn at one-half the rate of the crankshaft. Many high-performance engines have four valves per cylinder two for intake, two for exhaust , and this arrangement requires two camshafts per bank of cylinders, hence the phrase "dual overhead cams. The ignition system Figure 6 produces a high-voltage electrical charge and transmits it to the spark plugs via ignition wires.