# What is CC??
My bike is 150 cc, my bike is 110 cc. Fezar is 150 cc and Livo is 110 cc. My bike is 150 cc and so, your bike can not see my tail light. But actually what is CC. What does the meaning of engine’s CC.
In the era of internet maximum people used to know about it but still we have discussed it today. Today we would like to talk about an easy and common thing CC.
Piston used to up down in a cylindrical shape. The head of piston once touched the top dead center (TDC) and bottom dead center (BDC). CC means Centimeter Cube or Cubic Centimeter which is an unit of volume measurement. In a cylindrical shape, piston used to touch the TDC and BDC. The space between TDC and BDC used to be called by Centimeter Cube (cm3) of an engine or shortly CC. It is also called Swept Volume. In the case of multi cylinder engine, the sum total of each cylinder cc is the total engine’s cc.
Cylinder Volume = (πD^2L)/4
π = Pi, which is a constant and it’s value 3.1416
D = Cylinder Diameter
L = Cylinder Length
And in the case of engine, cylinder diameter is called as Bore and cylinder length (BDC point to TDC point) is called as Stroke.
Let’s come to the example of Yamaha Fzs or Fazer FI. It is a 149 cc bike. Let’s see how it is calculated as 149 cc.
As stated by the bike’s specification,
it’s Bore (D) = 57.3 mm = 5.73 cm
Stroke (L) = 57.9 mm = 5.79 cm
So, it’s Swept Volume = (πD^2L)/4 = 3.1416 × (5.73) ^ 2 × 5.79/ 4 = 149.30 = 149 cm3
So, Yamaha Fzs or Yamaha Fazer FI is 149 cc bike which is called as 150 cc as well. The higher the CC, the engine will be as strong.
Considering gasoline or Petrol engine the 1st stroke of four stroke bike is ‘Intake Stroke’ stage where a piston when moves TDC to BDC, then the engine’s cc can receive same volume of fuel -air mixer. According to the compression ratio, the volume mixer is compressed and it generates spark ignition to 3rd stroke ‘Power Stroke’. So, the more the CC, the more volume fuel – air mixer will go to ‘Intake Stroke’. By comabsting them the more power can be generated. So, if the cc would be higher, from engine the more power can be produced.
# 4 Stroke Engine Mechanism:
# Compression Ratio:
For compression there is a little volume just above the TDC which is called Clearance Volume but it is not counted among the CC. The volume between TDC point and BDC point is only called CC.
The volume of the engine’s cc or Swept Volume fuel – air mixed which is compressed by multiplying how many times with the 2nd stroke of 4 stroke engine ‘Compression Stroke’ step. That is called compression ratio.
The petrol engine’s ratio is 8 to 14
Diesel engine’s ratio is 16 to 20.
Like an example, the compression ratio of Yamaha Fzs FI is 9.5: 1 means fuel air gas which receives through intake stroke, the engine’s compression stroke compress it by 9.5 times multiply and then through the ‘Power Stroke’ it is ignitioned. Generally, the more the compression ratio, the more power used to generate.
# Did you observe one thing?
CC depends on two numbers. (Single Cylinder)
- Cylinder Bore or Cylinder Diameter
- 2. Cylinder Stroke or Cylinder Length
So, it has seen that by keeping cylinder same just increasing the bore and reducing the stroke, one kind of engine can be made or by reducing bore and increasing stroke, a different cylinder pattern engine can be created. And in each case of pattern, the features will be far different.
There are 3 types of engine can be made by changing some features.
- Over Square Engine
- 2. Square Engine
- 3. Under Square Engine
Written by: Sahed Ahsan Abir [Moderator at Fuel Injection Club BD- FCB]
Translated by: Ariful Islam (Apu)