Water Injection

Here is a picture of an Aquamist water injection kit with an advanced control computer for more precise water delivery.

Water is truly amazing. By being split into hydrogen and oxygen, water can be used as a combustible fuel. But what most people don't know is that regular water can be used without any special conversion or additives to boost fuel octane in high performance engines.

 

Contrary to popular belief, fuel octane is NOT the power rating of gasoline like many people believe. Octane is simply the ability of a fuel to resist spontaneous combustion. If a fuel combusts before the spark plug fires, then it creates a violent explosion called "detonation." Detonation can blow a head gasket due to excessive cylinder pressure. Severe prolonged detonation can even destroy a piston by breaking off the ring lands. Detonation must be avoided, hence the development of special high octane racing fuels.

By spraying a fine mist of water into the combustion chamber, fuel octane can be drastically improved. This is the basic premise of water injection. Cool water reduces combustion chamber hot spots, and it slows the explosive energy of gasoline preventing detonation.

The energy required to make a liquid turn into a vapor is known as the "latent heat of vaporization." Water can absorb an unbelievable amount of heat before it turns into steam, therefore it has a very high latent heat rating. This energy absorbing quality of water makes it perfect for cooling high performance engines, especially high performance turbocharged engines.

Water injection not only reduces detonation, but it also improves fuel economy. In airplane engines during WWII, engineers determined that you could reduce fuel consumption by 25% at full boost by using water injection. The idea is that you can use a much leaner fuel mixture with water injection, instead of using heavy fuel loads to cool the combustion process.

Ironically, water injection can be used on water fuel cell cars that are powered by liberated hydrogen from water! An engine can be ran solely on water, in one form it can be converted into hydrogen, and in another, the water is used to cool and control combustion. Theoretically, this engine this engine could have the same performance as an engine running on exotic race fuels. The only downside is that the water injection delivery systems today are either extremely crude, or extremely expensive. A lack of mainstream awareness makes water injection harder to setup and more expensive. As for saving the environment, and improving fuel economy, water injection is highly recommended.

 

What is Detonation ?

Normal gasoline car engines use spark plugs to ignite the fuel mixture. The spark is timed precisely to match the engine design, the engine speed, the engine load, and the type of fuel being used.

In high compression engines using a low octane fuel, the piston can compress the gasoline vapor (or other fuel vapor) in the combustion chamber so quickly, and with so much pressure, that the vapor could spontaneously combust. The fuel mixture is ignited by heat and pressure, not by the spark plug. This is known as detonation. Detonation causes a pinging sound. Regular gasoline, ethanol, kerosene, natural gas, propane and hydrogen are supposed to burn in a smooth controlled manner within the combustion chamber. Detonation causes the fuel to explode. Detonation can be caused by a hot spot, early (advanced) spark timing, low octane fuel, fuel impurities, wrong fuel additives, turbocharging or supercharging, engine design flaws, high outside air temperature, high engine temperature, and low intake air velocity.

In order to prevent detonation, we often have to lower the performance of the engine. Since this isn't practical, we are forced to use racing fuel. Racing fuel is specially designed to resist spontaneous combustion (detonation). Racing fuel is also very expensive, especially when used in a high performance vehicle.

Turbocharged and supercharged (forced induction) engines can have severe detonation because they are pumping hot compressed air into the combustion chamber. They are making a bad situation worse. To cool the combustion chamber, an intercooler is used that cools the incoming air. An extremely rich fuel mixture is used that prevents the engine from running lean under boost.