Skip to main content

Compression Ratio Of IC Engine in Simple Words

Compression Ratio Of IC Engine in Simple Words

Compression Ratio Of IC Engine in Simple Words. This is the main topic of today's post. Here, you will learn about the compression ratio of different combustion engines. I will cover important points like, what is compression ratio in automobiles? Why do petrol and diesel have different compression ratios? All such types of questions are simplified in this article. So, let's dive in. 

Compression Ratio Of IC Engine

What is Compression Ratio in Automobile?

It is the ratio between the volume of the cylinder when the piston is at BDC to the volume of the cylinder when the piston is at TDC. This is known as the compression ratio in automobiles. TDC and BDC are the top and bottom positions of cylinders where the piston moves up and down. The full form of TDC is Top Dead Center and BDC is Bottom Dead Center. Here, the cylinder is referred to as the combustion chamber of the petrol or diesel engine.
Have a look at the image - there you will easily understand that 10 grams of the air-fuel mixture are being compressed and made to 1. Hence, The ratio will be 10:1. 

Need For Compression In IC Engine

There are four strokes performed inside the cylinder block. Suction, compression, power, exhaust. Out of these 4 strokes, the compression stroke is the most important form of all. However, we get power from the power stroke. But, to get that power, the engine needs to get ready and be prepared for the power stroke. As we know, compression stroke comes before the power stroke, so it becomes crucial to compress the air-fuel mixture carefully and accurately. It must be very accurate as per the calculations. If a little bit of mistake is found anywhere, then the engine will start knocking. It is very difficult to diagnose such problems. This is why compression stroke is the most important of all.

Compression Ratio Of Diesel And Petrol Engine

Petroleum and Diesel are two different kinds of fuels. The compression ratio of petrol is 8:1 to 12:1 while the compression ratio of diesel engines is 14:1 to 22:1. Generally, the compression ratio of diesel engines is always higher than that of petrol engines.
We all know petrol is gasoline fuel and highly inflammable and needs no or little spark to cause a fire. But diesel is not like that. It takes time to catch fire. In this case, we need some heat and that is obtained by compressing the air in the combustion chamber. 
I hope you have noticed. There is no spark plug in the diesel engine. This is one of the reasons for not using spark plugs in diesel engines.

How to increase the compression ratio of an engine?

The compression ratio of engines can be increased by using heavier components inside the cylinder block.

Advantages and Disadvantages Of higher Compression Ratio

There are a few pros of cons of a higher compression ratio. 
When the compression ratio is high, there will be more temperature and pressure inside the cylinder. It will result in the complete burning of fuel. And we will get better acceleration and mileage. On the other hand, it will make the engine heavier and engine operation can be noisy. Sometimes, you may find knocking also.

Also, read about CRDI in very simple words.
Tags

Comments

Post a Comment

Popular Posts

Does EGR system Decreases Engine Power? (Must Know)

Does EGR system Decrease Engine Power? You will be shocked to know that the EGR system in automobiles decreases the volumetric efficiency as well as power output.  Yes, you heard it right. Then, you must be thinking. why are we using EGR? What it actually does? Does it do any other thing to the engine? All these doubts and topics are covered in this article. Let's get started. Little Intro to EGR EGR stands for Exhaust Gas Recirculation System . It is part of em mission control system in an automobile vehicle. It has zero roles in increasing engine power. It is used in vehicles to stop the formation of NOx gas. Which are very harmful to nature. Generally, when a vehicle runs on the road it produces lots of smoke and pollutants like carbon monoxide, carbon dioxide, and the most dangerous one i.e. oxides of nitrogen . Formation of NOx Fas Inside Engines Cylinder It is essential to know how and when NOx is formed inside an engine's combustion chamber. Nitrogen and oxygen are...
1 comment
Read more

What is Turbocharger? Turbo Lag, WasteGate Valve

What is Turbocharger? Turbo Lag, WasteGate Valve Getting a turbocharged vehicle is exciting but before you start the first thing that comes into your mind. In this article, I have shared the topics like What is Turbocharger , Turbo Lag , WasteGate Valve , and many other short questions and doubts related to the turbocharger. What is Turbocharger? How Does it Work? A turbocharger is a forced induction device which added to the engine to increase the volumetric efficiency of an engine. It is powered by the flow of exhaust gases coming out of the engine. It does not require any additional power or battery to run.  It compresses the intake air and forces more air into the intake manifold. Compressed air is cooled down with the help of an intercooler before sending it to the engine intake. Which helps to produce more power. A turbocharger helps to reduce emissions at high RPM. It is also known as a high-altitude compensation kit. Turbocharger Construction The design of the turbochar...
1 comment
Read more

CRDI (Explained In Very Simple Words)

CRDI - Common Rail Direct Injection (Hyundai) CRDI means a common rail direct injection system. It is a type of fuel delivery system used in most cars and vehicles. In this system, fuel is taken out and delivered into the engine's combustion chamber. CRDI is the name used by Hyundai and other brands that call the same system different names. Like, DICOR , CRDE, and DDIS , the three are the same but are used by various companies like TATA , Mahindra , and Maruti . What is CRDI? CRDI is the most advanced form of fuel delivery system which is fully automatic and controlled by ECU . And here, ECU works on the data provided by the actuators and sensors. This system is mostly used by Hyundai( a motor company).  Is CRDI and MPFI the same? No, both are different. CRDI is used in diesel engines whereas MPFI is used in petrol engines. Parts/components used in the CRDI system The main working components of the CRDI are: Fuel tank Fuel filter Pump Pressure Regulating Valve High-pressure Pu...
1 comment
Read more