Definition, How It Works, And The Difference Between 4 Stroke And 2 Stroke Engines

 Definition, How It Works, And The Difference Between 4 Stroke And 2 Stroke Engines

Then you will often hear the words 4 stroke and 2 stroke engines. Generally these words are often used when talking about motorbikes.

This is because when we look back 15 years, motorbikes in Indonesia used 4-stroke and 2-stroke engines.

If they understand motorbike engines, it's good to understand.

But what about those who don't understand this at all?

Don't worry, we will explain several things such as the meaning, how it works, and the differences between a 4-stroke engine and a 2-stroke engine. 

Understanding 4 Stroke Engines

So, what does a 4 stroke motorbike engine and a 2 stroke engine mean?

According to most Indonesians, the word "tak" is taken from the word stroke .

The word in question aims to identify the vehicle engine.

A 4 stroke engine indicates that it has 4 steps that occur in the combustion process in the engine room. 

While 2 does not, there are only 2 steps that occur in the combustion chamber.

In general, the majority of motorbikes in Indonesia today are 4 stroke. 

The aim of using a 4-stroke engine is to produce environmentally friendly and fuel-efficient emissions.

On the other hand, 2-stroke motorbike engines usually produce more smoke from the exhaust. 

The resulting exhaust sound will of course be noisier than a 4-stroke motorbike.

Some examples of 2-stroke motorbikes include the Yamaha RX-King, Suzuki Satria gen 1 and 2, Kawasaki Ninja RR, and many others.

How the 4 stroke engine works

Are you curious about how a 4 stroke engine works?

What are the 4 steps that occur in this combustion chamber?

Intake Stroke (suction stroke)

The first step is the intake stroke or suction step.

In this first step, the piston in the engine will move from top dead center to bottom dead center.

Simultaneously, the suction valve between the carburetor and the combustion chamber will open.

This is what allows the mixture of fuel and air to enter the cylinder space.

Compression (compression stroke)

In this second stroke, the piston will move in the opposite direction from bottom dead center to top dead center.

This will cause the suction valve to close which will cause the rising piston to block the mixture of fuel and air in the cylinder chamber.

The effect is that the air temperature will be higher.

Combustion

Then the next step is compression of the fuel produced from air at high pressure and temperature. 

This will cause the spark plug to spark which will then burn the hot fuel and air mixture.

This is where an explosion occurs which will make the piston from top dead center to bottom dead center.

This up and down movement of the piston will then make the crankshaft rotate to produce power.

Exhausted

Then the final step is disposal. Because, in the name of burning, there must be disposal.

In this step, the piston moves again from bottom dead center to top dead center which simultaneously occurs at the exhaust valve discharge. 

So, the residual combustion gas that occurs will later be removed from the exhaust valve to be expelled through the exhaust hole on the motorbike.

After being discharged, this machine cycle will be repeated again in the suction cycle and so on until it is discharged again.

Understanding 2 Stroke Engines

Then, what about 2-stroke engines? What's the difference?

A 2-stroke engine only has 2 steps that occur in the combustion cycle.

This can be seen from the disappearance of the intake and exhaust valves which are like those on a 4 stroke.

First step

In a 2-stroke engine, the piston will move up first. The exhaust and rinse channels will be closed by the piston, and this is where petrol gas will become blocked in the combustion chamber.

When the piston is at top dead center, combustion will occur caused by gasoline vapor which is directly exposed to the flame from the spark plug.

When the piston is up, the inlet hole will open. The new gasoline gas in the carburetor will enter the combustion chamber.

Second Step

Then when the piston descends from top dead center, the combustion exhaust channel will open, followed by the opening of the flush hole channel.

This combustion gas will later be thrown outside by blowing gasoline from the flushing channel. 

When the piston is at bottom dead center, new gasoline vapor will enter from the inlet.

Then the piston will move up and repeat the process like the first step. 

Why is 2 Stroke Faster?

Of course, many people wonder, why is the performance of a 2-stroke motorbike engine faster than a 4-stroke motorbike? What's the reason?

The answer can of course be seen from the process of a 2-stroke motorbike engine taking fewer steps than a 4-stroke. 

Motorcycles with 2 stroke engines only have 2 steps, while 4 strokes have 4 steps in the combustion cycle.

Therefore, 2-stroke motorbikes have faster performance than 4-strokes.

But it must also be acknowledged that 2-stroke motorbike engines usually have higher fuel consumption and higher exhaust emissions. 

Advantages & Disadvantages of 4 Stroke and 2 Stroke Engines

Both 4-stroke and 2-stroke motorbike engines have their own pluses and minuses, aka advantages and disadvantages.

4 stroke motorbikes usually have shortcomings in terms of maintenance.

According to several sources, 4-stroke motorbikes are considered to require more attention to maintenance.

Meanwhile, 2-stroke motorbikes are considered to require less maintenance.

However, this will of course differ in each person's perception.

There are those who think that 4-stroke motorbikes are more stubborn, but there are also those who say that 2-stroke motorbikes are much easier to maintain.

However, it must be admitted that the maintenance costs for a 4 stroke are much cheaper than a 2 stroke.

This can be seen from the use of side oil on the 2 stroke.

2-stroke motorbikes must use side oil to lubricate the engine's internal components.

This side oil will then circulate up to the cylinder header.