Hey guys,in the last class, we have discussed about Types of Oil filters and Types of lubrication systems in a detailed way.you can check it here and now, in the today’s article, we can discuss about Types of Fuel Supply System in SI Engine briefly.

Note: Download Types of Fuel Supply System in SI Engine PDF at the end of the article. 

Types of Fuel Supply System in SI Engine
Types of Fuel Supply System in SI Engine

Types of Fuel Supply System in SI Engine:

In automobiles, the basic fuel supply system with petrol engine consists of 

  • a fuel tank
  • fuel pump 
  • fuel lines 
  • air cleaner 
  • fuel filter 
  • carburettor 
  • inlet manifold 
  • supply and return pipe lines

Following are the types of systems which have been used for the supply of fuel from the fuel tank to the engine cylinder.

  1. Gravity system 
  2. Pressure system 
  3. Pump system 
  4. Fuel Injection System

Gravity system,pressure system and pump system make use of the carburettor whereas the fuel injection system does not use carburettor for the Air/Fuel supply.

The Gravity system is confined to two wheelers only whereas the Pressure and the Vacuum systems are almost obsolete now.

The Pump system is widely used in automobiles and due to certain advantages, the usage of Fuel injection system is rapidly increasing in modern vehicles.

The detailed explanation of Fuel Supply systems is as follows…

1.Gravity System:

  • In this system, the fuel tank is mounted at the highest position from where, the fuel drops into the carburettor float chamber by gravity.
  • The system is very simple and cheap.

2.Pressure system:

  • In the pressure system, a sealed fuel tank is used and the pressure is created in the tank by means of either engine exhaust or a separate air pump.
  • For starting, the pump is primed by means of hand.
  • It is under pressure thus producing the fuel flows to the float chamber of the carburettor.

There are chances of pressure leak but the advantages lie in the fact that the fuel tank can be placed at any suitable location.

3.Pump System:

In this system, a steel pipe is used to carry petrol from the fuel tank to the fuel pump, which pumps it into the float chamber of the carburettor through a flexible pipe.

Mechanical pump is driven from the engine camshaft.

However electrically operated fuel pumps can be placed anywhere, away from the hot engine in reducing the tendency of forming vapour lock and this system is commonly used in the present day cars.

4.Fuel Injection system:

The petrol injection system has been used successfully on some modern vehicles.The petrol injection system is used in the place of Carburettor so that the desired quantity of fuel and air will reach all the cylinders.

The fuel is atomised by means of an injector nozzle and then delivered into the air stream.

Separate fuel injectors are used for each cylinder while the mixture under different load and speed conditions is controlled either mechanically or now more often electronically and this is the most accurate fuel supply system.

This is the explanation about Types of Fuel Supply System in SI Engine in a detailed way. If you have any doubts, you can comment us from the comments section.


Image Credits:

Image 1 is taken from the Text book of Automobile Engineering by Kirpal Singh

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Mohammed SHAFI

Mr. Mohammed Shafi is an Assistant Professor at Sreenidhi Institute of Science & Technology. By education, he is a Mechanical Engineer and expertise in CAD & CAM. Mechanical Students is his first...

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