Explaining Car Engines: How They Work


Think back a little under 150 years ago, and you may be surprised at how most people traveled. Usually, they had to ride a horse or walk. While horse-drawn carriages were available, they were nothing like the first initial vehicles, which have also changed throughout the years to incorporate more technology. Inventing the car may have been the best thing for the human race because it allows people to travel long distances without much fuss. However, learning about how the car moves and what the engine does can give you a greater understanding of just how magnificent these machines are.

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How They Get Power
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Petroleum is the primary way that most passenger vehicles get their power, though some cars and commercial trucks run on diesel fuel. Regardless of the fuel type, it’s all made from petroleum, which is also called crude oil. It’s black, thick, and full of energy and it’s buried in the ground, so it must first be pumped to the surface and then refined to create kerosene, diesel, and gasoline.

Petroleum fuel is made of hydrocarbons, which are primarily carbon and hydrogen molecules/atoms. Many other products contain the same hydrocarbons, and professionals can turn it into energy by burning it. However, burning it, say over a campfire, wastes more energy than burning it in a car engine. They’re highly efficient and waste much less energy and use more of the energy that’s created.

Primary Parts of the Engine

Car engines are basically built around cylinders. While most cars have four, six, or eight, they can have up to 12 or as little as two. These cylinders burn the fuel and are sealed shut and made of metal. At one end, the cylinder opens and closes, similar to a bicycle pump. They also include pistons, which are tight-fitting plungers that slide up/down inside. Each cylinder has two valves at the top, which lets things in/out and open/shut very quickly.

You’ve also got an inlet valve, which allows air and fuel to enter from the fuel injector or carburetor. The outlet valve is also included and allows exhaust gas to escape.

At the top, the cylinder also has a spark plug, which is electronically controlled to make a spark to set the fuel afire. The pistons are attached to a turning axle at the bottom of the cylinder, which is called a crankshaft. This powers the gearbox of the car and turns the wheels.

Four-stroke Engine: How it Makes Power

A car engine makes its power by repeating four primary steps throughout the drive. Therefore, you can imagine how often each step repeats when you run to the corner store or take a long trip.

Intake: The crankshaft provides the momentum to make the piston pull down inside the cylinder. The crankshaft usually turns for as long as the car is moving. The inlet valve opens to let a mixture of air and fuel into the cylinder.

Compression: Immediately, the inlet valve closes while the piston moves up through the cylinder and compresses that fuel-air mixture, making it more flammable. When the piston reaches the top again, the spark plug fires.

Power: The power is created when the spark ignites the air-fuel mixture and causes a mini explosion. You don’t hear this noise, but it causes the fuel to burn immediately, producing a hot gas that forces the piston back downward. The energy from the fuel now powers the crankshaft.

Exhaust: The outlet valve on the opposite side of the inlet valve now opens. The crankshaft continues turning, and the piston is propelled back upward for a second time. The piston forces the exhaust gas from the burned fuel to go out through the exhaust outlet.

The cycle above then repeats itself while the car is moving.

Cylinder Size and Amount

The four-stroke engine design does have one flaw because the crankshaft that powers the cylinder is only one stage. Therefore, most cars have four cylinders at least, arranged in such a way that they fire out-of-step with each other. That way, each cylinder is always going through a different stage, allowing the fuel to constantly provide power to the crankshaft. With a full 12-cylinder engine, you have three cylinders that power the crankshaft at one time. They’re typically used for powerful and extremely fast cars.

While the amount of cylinders is important, it’s also essential to focus on their size, as each cylinder has to produce enough power to propel the car forward.

There are two primary measurements to consider, including the diameter and the stroke of the piston (how far it moves out). There are many mathematical equations designed to find the area of a circle, the radius, and volume of the cylinder. If you want to customize the engine of your vehicle, you are going to need to figure out the equations so that you can ensure that the cylinders are appropriate for your needs.

Cleaner Engines

Many carmakers have chosen to include hybrids or full-on electric cars, which means some people wonder why they still make fuel-based engines. These are more popular with consumers because they understand them better.

Of course, pollution is the primary concern here; with roughly a billion cars owned by consumers, the pollution produced can be astronomical. In fact, it’s a serious problem that the government has tried to fix over the years. They have made some headway by keeping vehicle emissions low and creating safer-for-the-planet gasoline but getting all the vehicles to run on it isn’t easy.

While saving the planet is a primary concern for many consumers, consumers still buy gasoline-powered vehicles because petroleum still packs more energy into every kilogram/liter than any other substance, including electricity. Even so, cars and engines aren’t perfect. There are many steps between the cylinders and the wheels, and some energy is always going to be wasted. Therefore, you can expect that for every dollar you add to the gas tank, about 85 cents are wasted in a multitude of ways.

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Explaining Car Engines: How They Work

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