How Does an Engine Work?

The engine is the heart of the car. Just like the human heart pumps blood to power the body, the engine converts fuel into motion to make the vehicle move. But… how does all this magic happen inside a metal block?

Let’s break it down simply.

1. The Basic Idea

An engine is built on one simple concept:

Burning fuel to create small explosions that move parts inside the engine.

These repeated explosions are what push the car forward.

2. What’s Inside the Engine?

Inside the engine, you’ll find:

• Cylinders

• Pistons that move up and down inside them

• Valves that let air and fuel in and out

• Spark plugs that create the ignition

Imagine the cylinder as a small tube, and the piston as a piece that slides up and down inside it.

3. The Four-Stroke Cycle

All internal combustion engines work using the same cycle called
the four-stroke cycle:

1. Intake Stroke

• The piston moves down

• The intake valve opens

• Air and fuel enter the cylinder

The engine is “taking a deep breath.”

2. Compression Stroke

• The piston moves up

• Both valves close

• The air-fuel mixture is compressed

Like squeezing a spring inside a small space.

3. Power Stroke (Combustion)

• The spark plug fires

• The mixture explodes

• The piston is pushed down with force

This is the moment where power is created.

4. Exhaust Stroke

• The piston moves up again

• The exhaust valve opens

• Burned gases are pushed out

The engine “exhales” before starting the cycle again.

4. How Do Pistons Create Car Movement?

Pistons alone don’t move the car. They are attached to:

The crankshaft

As the pistons move up and down, the crankshaft converts this into rotational motion.
This rotation travels through:

• The transmission

• The driveshaft

• The wheels

And that’s how the car moves.

5. What About Modern Engines?

Modern engines use advanced systems to make combustion more efficient:

• Turbochargers to push more air into the cylinders

• Direct fuel injection

• Sensors to control air, fuel, and timing

All of this increases power while reducing fuel consumption.

6. Types of Engines

Common engine types include:

• 4-cylinder engines

• V-type engines like V6 and V8

• Hybrid engines

• Electric motors (which work very differently)