Metro Works: Gasoline Engines

When most people think of engines, they probably think of the gasoline-powered kind. These engines are found in millions of vehicles all over the world and are responsible for turning the rotational energy of the engine into kinetic energy that can move a car forward.

Learn About Gasoline-Powered Engines And How They Work

In this blog post, we will take a closer look at how these engines work and some of the different components that make them up.

The Main Components Of A Gasoline Engine

  • Pistons
  • Cylinders
  • Valves
  • Crankshaft
  • Camshaft


The pistons move up and down in the cylinders to create compression and expansion of the air/fuel mixture. The pistons are connected to the crankshaft, which converts the linear motion of the pistons into rotational energy. This rotational energy powers the car’s wheels. 

There are many different types of pistons used in engines today. Some pistons use two compression rings and one oil ring while others use three compression rings. The type of rings used on a piston depend on the application and the type of engine. 

Pistons can be made from cast iron or aluminum alloys. Aluminum pistons are typically lighter than cast iron pistons and have better heat transfer properties. Cast iron pistons are more durable but can be more prone to wear and tear over time.


The Cylinders in a car engine are what create the power that makes the car move. The Cylinders work by taking in air and fuel, then using the spark plugs to ignite the mixture. This creates an explosion that forces the pistons down, which in turn moves the crankshaft and causes the car to move. Cylinders come in different sizes, depending on how much power the engine needs. Larger engines typically have more Cylinders than smaller ones. Cylinder bore is also an important factor, as it determines how much air and fuel can be taken in. Too small of a bore and you’ll lose performance, while too large of a bore will make the engine less efficient. 


The valves in a car engine are responsible for opening and closing the intake and exhaust ports. The valves are opened and closed by the camshaft, which is rotated by the crankshaft thru a belt or timing chain. The timing of the valve openings and closings is critical for proper engine operation. Cylinders are filled with air (or fuel and air) during the intake stroke, and the valves must close at just the right time to keep the air/fuel mixture from escaping past them. The exhaust stroke removes the spent air/fuel mixture from the cylinders, and the valves must open at just the right time to let it escape. If any of these things don’t happen correctly, you’ll end up with an engine that doesn’t run well (or at all).


The Crankshaft is one of the central pieces of a car engine. It is responsible for converting the linear motion of the pistons into rotational motion, which in turn powers the rest of the engine. The Crankshaft is a long, cylindrical shaft with several connecting rods attached to it. The connecting rods are fitted with small pistons that move up and down as the Crankshaft rotates. This motion creates compression and combustion in the engine cylinders, which powers the car.

The Crankshaft must be very strong and durable in order to withstand the high stresses and pressures associated with running a car engine. It is made from forged steel or cast iron, depending on its application. The Crankshaft is also fitted with bearings that allow it to rotate smoothly.


The Camshaft is a key part of the car engine. It sits in the engine block and is responsible for opening and closing the valves that let air and fuel into the cylinders. The Camshaft is rotated by the crankshaft, which means it moves up and down as the engine runs. This motion opens and closes the valves at just the right time to let in air and fuel and push out exhaust gas.

The Camshaft can be made from different materials, depending on how long it needs to last. Steel Camshafts are strong but can wear out quickly, while aluminum Camshafts are lighter but don’t last as long. Ceramic Camshafts are very strong and durable but also very expensive.

There are also different types of Camshafts, depending on how they work. Hydraulic Camshafts use oil pressure to actuate the valves, while Solid Camshafts use a lever to move the valves. Cam Phasing can also be used to change when the valves open and close, which can improve performance or fuel economy.

Gasoline engines are the most common type of engine in the world and are found in millions of vehicles. 

These engines work by converting rotational energy into kinetic energy, which can move a car forward. In this blog post, we looked at the main components of a gasoline engine and how they work together to create motion. If you have any questions about gasoline engines or want more information on how they work, please don’t hesitate to contact us or call. Our friendly front office staff and ASE Certified Technicians are here to help!

Metro Transmission

Metro Transmission

The ASE Certified Mechanics at Metro Transmission and Automotive have over 100 years of combined experience. We're a full service, AAA Approved Auto Repair Shop, conveniently located in San Marcos, CA off Highway 78.

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