How 4 Stroke Engines Work

How 4 Stroke Engines Work - A 4 stroke engine is a machine that in one working cycle consists of 4 piston strokes. What is piston stroke? here's the explanation

Piston Stroke

The piston stroke is the movement of the piston from Top Dead Center (TDC) to Bottom Dead Center (BDC).

So one stroke of the piston is from TDC to BDC or vice versa. Well, our vehicles generally use the type of internal combustion engine (internal combustion engine). What did it burn? of course fuel. That's why we always fill up when the tank is empty, right?

An example is a very useful motorcycle that we often use, it can move because it uses an engine (engine). The engine used can generate power to move the motorcycle and accelerate due to the stages in the engine. Simply put, this stage will convert the fuel into power and the energy can move the vehicle.

This stage is known as the 4 stroke/4 stroke motor cycle. why 4 steps? So the engine on the vehicle is designed in such a way as to be able to convert fuel into power in the form of rotary motion (to turn the wheels).

In the 4 stroke engine that we use to produce power, it takes 4 piston strokes consisting of:

1. Intake Stroke (TDC - BDC)
2. Compression Stroke (BDC - TDC)
3. Combustion Stroke (TDC - BD)
4. Exhaust Stroke (BDC - TDC)

Inside the engine, the piston performs translational motion (straight motion) from TDC to BDC, or vice versa. The movement of this piston is the core of a vehicle engine.

How Does a 4 Stroke Engine Work?

1. Intake Stroke

The way the first 4 stroke engine works is the intake stroke.

Piston Movement: Piston moves from TDC to BDC

Valve Position: The intake valve is open and the exhaust valve is closed

Occurrence: A mixture of fuel and air enters the cylinder

Crankshaft Turns: 180° (1/2 Turn)

The movement of the piston from TDC to BDC causes the cylinder chamber to become a vacuum. As a result of this vacuum, the air and fuel mixture enters the cylinder through the intake valve. So this suction stroke occurs if the pressure in the cylinder chamber is lower than atmospheric pressure.

2. Compression Stroke

The second way the 4 stroke engine works is the compression stroke.

Piston Movement: Piston moves from BDC to TDC

Valve Position: The intake valve is closed and the exhaust valve is closed

Occurrence: A mixture of air and fuel is compressed or compressed

Crankshaft Turns: 360° (1 Turn)

In the compression stroke, the air and fuel mixture is compressed. In this step there is a change in volume which makes the pressure and temperature rise so that the air and fuel mixture becomes easily flammable. Until the end of the compression stroke spark plugs spark and there is combustion.

The compression stroke theoretically begins when the piston is moving upwards. But actually, this compression stroke only occurs after the suction valve closes. The volume change that occurs in this compression stroke is from the total volume to a number of combustion chamber volumes.

3. Combustion Stroke

The third way the 4 stroke engine works is the combustion stroke.

Piston Movement: Piston moves from TDC to BDC

Valve Position: The intake valve is closed and the exhaust valve is closed

Occurrence: In this step, energy is generated

Crankshaft Turns: 540° (1 1/2 Turns)

The piston moves from TDC to BDC, both valves are closed. The piston moves towards TDC and in that condition the volume of the combustion chamber becomes smaller so that the pressure and temperature in the cylinder are higher. spark plugs so that the combustion process occurs.

The remaining combustion gases are able to push the piston to move back from TDC to BDC. In this step, energy is generated from the explosion of the combustion process.

4. Exhaust Stroke

The fourth way the 4 stroke engine works is the Exhaust stroke.

Piston Movement: Piston moves from BDC to TDC

Valve Position: The intake valve is closed and the exhaust valve is open

Occurrence: The residual combustion gas is discharged through the exhaust valve

Crankshaft Turns: 720° (2 Turns)

The piston moves from BDC to TDC. The intake valve is closed and the exhaust valve is open. The movement of the piston from BDC to TDC causes the residual combustion gases to be pushed out of the cylinder chamber, resulting in a reduction in volume and a reduction in pressure.

So on a 4 stroke gasoline motor in 1 cycle it requires 4 piston stroke and 2 crankshaft rotations. For more details, see the image below!

The 4 steps above are how the 4 stroke engine works, there is also the 2 stroke engine which is different from the 4 stroke engine.