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Fuel Efficiency Improvement and Knocking Reduction System

Published on Feb 12, 2017


In internal combustion engines, water injection, also known as anti-detonant injection, is spraying water into the cylinder or incoming fuel-air mixture to cool the combustion chambers of the engine, allowing for greater compression ratios and largely eliminating the problem of engine knocking (detonation). This effectively reduces the air intake temperature in the combustion chamber, meaning that performance gains can be obtained when used in conjunction with a supercharger, turbocharger, altered spark ignition timing, and other modifications.

The reduction of the air intake temperature allows for a more aggressive ignition timing to be employed, which increases the power output of the engine. Depending on the engine, improvements in power and fuel efficiency can also be obtained solely by injecting water. Water injection may also be used to reduce NOx or carbon monoxide emissions.


This project consists of a small water tank, pump, microcontroller unit, engine set up and fuel injector. The microcontroller unit is used to setting the water injection period. The pump is used to suction the water in to deliver the fuel injector. The 12volt fuel injector is used to inject the water in to the cylinder. This 12v fuel injector is controlled by the microcontroller unit.


The Pressurized fuel is given to the input supply of this fuel injector. The 12volt pump is used to suction the water from the water tank and is given to the fuel injector. The fuel injector is controlled by the microcontroller unit. The fuel and air is supplied from the carburetor already used in the petrol engine. The 12v power supply is given to the fuel injector coil. The coil gets energized to open the nozzle hole so that the pressurized water sprayed by the injector nozzle.

Engine power production, referred to as brake mean effective pressure (BMEP), is measured by taking the average effective pressure of the cylinders as they progress through intake, compression, ignition, and exhaust strokes. Added power comes as a result of greater pressure, but a higher temperature inside the cylinder accompanies greater pressure. These higher temperatures can lead to detonation, referred to as engine knock, or pre-ignition, both of which are cases where the fuel-air mixture burns in an undesirable manner and can be destructive to an engine.

To combat knock and pre-ignition as power increases, a richer air-to-fuel ratio is normally required. If the addition of extra fuel doesn’t provide enough knock protection, then a higher-octane fuel, which is more resistant to knock and pre-ignition, may be used. However, once the knock limit of a higher-octane fuel is reached, can anything be done? This is where a water injection system presents an appealing option.


Fuel Efficiency Improvement


• All Petrol Engine Application.

• In Automobile Quality control unit.

• Two wheeler Application.


• It requires simple maintenance cares.

• This method is fuel saving method.

• Checking and cleaning are easy, because of the main parts are screwed.

• Repairing is easy.

• Replacement of parts is easy.

• To reduce the NOx or carbon monoxide emissions.


• Initial cost is required to install this testing equipment.

• Some coolant oil requires to mix into water tank

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