Water Injection
- Fine Water Mist
More Power and Fuel Economy from water? Fact or fiction? No, we are not talking about new developments on the use of hydrogen for the future but rather the simple use of the humble tap water. We are talking about water injection systems for both normal aspirated and turbocharged engines and not the simple water spray systems onto the intercooler some enthusiasts may associate with turbocharged cars. Water injection systems actually spray a fine mist of water directly into the combustion chamber. Yes, that is right, water mixed with your air and fuel! It might seem strange to be injecting water into an internal combustion engine; however there are several benefits to doing this. This is not new and was used in WW2 fighter aircraft to increase peak power during combat.
Heat is the major problem in engines and more so in our climate. It quickly damages engine components and is often the limiting factor in extracting the maximum performance. Combustion temperature can easily exceed 1000 degrees C, especially at high turbo or supercharger boost. Water injection cools the flame and thus permits much higher boost settings for higher power output.
In a water injection system, fine droplets of water explode into steam during combustion. This dramatic volume increase helps power the engine while at the same time quenching the flame temperature.
Fuel burns only the fuel vapor burns. Liquid fuel droplets don’t combust and so don’t contribute to powering the engine. Today’s EFI systems don’t provide efficient fuel vaporization. What they do is accurately meter the fuel, and much of the fuel is still in the form of small droplets during combustion. The heat vaporizes this liquid that can then ignite at some time later, late in the power stroke and even continuing during the exhaust stroke. This is obviously not very efficient and nearly all of the high mileage devices today and throughout history have been based on improving the fuel vaporization prior to the initial combustion.
Something else very interesting is happening here that you may have realized. The liquid fuel which is vaporizing during combustion is quenching the flame, extracting heat to boil off and thus cooling the flame. When it does eventually burn completely, the final temperature that is achieved will be less than you would think because of the expansion and work output during the power stroke. Water injection allows us to cut back this wasted fuel.
If you adjust your mixture to slightly lean then the flame temperature will increase. Less fuel > more heat. You get better fuel economy with a slightly lean mixture but you risk heat damage, and the maximum available power will be reduced.
Modern light engines often have a mixture control which can be adjusted to increase cruising range by operating slightly lean. It is standard procedure to increase the mixture to a richer state if the temperature rises too high. They use fuel to cool the engine. The same wasteful use of fuel is happening inside your motor car. Your vehicle would get better fuel economy if operating lean, but it would overheat and suffer damage, unless you use water to cool the flame.
Water injection:
- Prolongs engine life by controlling heat.
- Allows for improved fuel economy by running leaner mixtures.
- Keeps the cylinders and pistons clean by continuously steam cleaning.
- Helps prevent pinging by cleaning away carbon deposits and cooling the combustion process.
- Reduces oxides of nitrogen pollutants by reducing the temperature.
- Allows greater ignition timing advance.
- Permits higher boost levels on turbo engines.
Water injection by itself will bring about some increases in power/torque and fuel consumption as the car’s ECU will make some adjustments to the ignition timing itself. To get the optimal advantage from water injection, you need to reprogram the car’s ECU via Flash Programming if available or via Piggyback ECUs such as Unichip, Emanage Utilmate etc.
By the way guys, all those Hydrogen thingy you get from Ebay don’t work as they do not produce enough hydrogen. Save your money for other stuff.
