How does engine work?

In the modern world, travelling is simpler than it ever was. We have access to many different vehicles, each having its own advantages over others. One thing all those have in common is - the engine. There are many kinds of engines, but we will explain the one which can be found in cars.

Engine parts

The engine is obviously really complex, but the principle behind its work is relatively simple. But first, let's see what it contains.
The engine can be divided into 2 main parts - block and head, with head gasket in between. Block contains several pistons and cylinders (usually 4 or 6), and head holds valves, fuel injection and ignition systems, all needed for pistons' work.

Parts of an engine. Credits: https://www.carthrottle.com/post/head-gasket-failure-check-yourself-before-you-wreck-yourself/

Work process

You may have heard of "four-stroke" - a term used to describe the cycle of an engine's piston.
Step 1 - Intake. The piston moves down, creating a vacuum, and pulling air in through intake valves. Fuel is added into the air, creating a highly flammable mixture.
Step 2 - Compression. The piston moves up, compressing air and fuel.
Step 3 - Power. An ignition system creates a spark, igniting the fuel and starting a controlled explosion. The explosion pushed the piston back down.
Step 4 - Exhaust. While the piston goes up, it pushes used gas into exhaust pipes and out of the vehicle.
When the piston moves (during all 4 stages), it rotates the internal shaft (crankshaft), which rotates the vehicle's wheels or propellers.

Four-stroke cycle. Credits: https://www.britannica.com/technology/four-stroke-cycle

Engine types

Depending on the position of the pistons, there are a couple of engine designs. When all pistons are arranged in a row, it is a inline engine. If pistons are grouped into 2 banks connected at an angle, creating a "V" shape, it is a V-engine. Finally, when the angle between these banks is 180°, that is a boxer (flat) engine.

V-engine. Credits: https://www.dubizzle.com/blog/cars/v-engines/