Does water injection (into an internal combustion engine) work?

Question

Are there any aftermarket kits out there that can be retrofitted to your car's engine? And do they increase performance and add to overal gas mileage?

Answer 1

Water injection is a method for cooling the combustion chambers of engines by adding water to the incoming fuel-air mixture, allowing for greater compression ratios and largely eliminating the problem of engine knocking. This effectively increases the octane rating of the fuel, meaning that performance gains can be obtained when used in conjunction with a supercharger or turbocharger, altered spark ignition timing, and other modifications. Many water injection systems use a mixture of water and alcohol (usually 50/50), partly because the alcohol is combustible, while water is not; in addition, the alcohol serves as an antifreeze for the water. Hence, water injection is also often known as methanol-water injection, owing to the fact that the alcohol mixed into the injection solution is often methanol, CH3OH.

NOTE: Due to its corrosive nature, the alcohol in water injection systems cannot be ethanol. Only methanol and isopropanol are used, methanol being the more commonly-utilised form of alcohol for this purpose due to its higher availability and lower cost than isopropanol.

Water injection is often necessary when adding forced induction to an engine that was not designed for it; the compression ratio of a normally-aspirated engine is too high to cope with more than a very modest boost, even with retarded ignition timing, unless this technique is used.

The system was first used extensively on World War II fighter aircraft to increase power upon takeoff and bring up the service ceiling. A limited number of road vehicles with large-displacement engines from manufacturers such as Chrysler have also included water injection. Saab offered water injection for the Saab 99 Turbo. With the introduction of the intercooler the interest in water injection disappeared, but today, water injection is also of interest because it can potentially decrease nitrogen oxide (NOx) emissions in exhaust. Water injection is primarily used with piston-powered internal combustion engines, but it has also seen use with turbines.

The initial injection of water cools the fuel-air mixture somewhat, which may allow for more mixture to enter the cylinder. But the greater effect comes later during combustion when the water takes in significant amounts of heat energy as it converts from liquid to gas (steam), increasing piston pressure (torque) and reducing the peak temperature with its resultant NOx formation as well as the amount of energy absorbed into the cylinder walls. The duration of combustion is said to be longer. An interesting side effect that has been reported by some is that water injection effectively "steam cleans" the engine interior, resulting in less carbon residue buildup. Glowing hot carbon deposits are a known cause of knocking.

Fuel economy can be improved with water injection, although the effect on most engines with no other modification, like leaning out the mixture, appears to be rather limited or even negligible in some cases.

Some degree of control over the water injection is important. It needs to be injected only when the engine is heavily loaded and the throttle is wide open; as with other systems which need to monitor engine load, this can be determined by manifold vacuum, which is low when the engine is loaded and high when it is unloaded; however, provision must be made for starting, when the manifold vacuum is also low but water injection is undesirable.

Reports of more rapid corrosion of the steel and cast iron components of engines to which water injection has been added suggest that more frequent oil changes, particularly when the engine does not experience sustained high temperature operation to evaporate any water from the oil, are prudent.

It's been used in many competition and autocross cars for years.

As to the comment about it being "snake oil." Tell that to the military which continues to use it to this day to improve the engine performance on certain aircraft.

Answer 2

Water Combustion Engine

Answer 3

Actually, water injection helps to cool the engine in hot environments and slows combustion to improve economy. It would require filling another reservoir.
My father, 85, used to swear by his and he kept one on all his vehicles until he no longer worked on them.
There are still kit still around.
They may just work by reducing the proportion of intake charge that is fuel and air. (like driving on a rainy day)
The higher the humidity the less there is of oxygen and fuel in each intake.

Answer 4

I think you do mean actually injecting water into the carb or the intake to boost combustion for increased gas mileage and/or performance.

There used to be bunches and bunches of such products to be found on J.C. Whitney along with a spiel about all the miracle cures it'd perform. About the only thing it didn't claim to do was cure cancer.

Didn't work then and it won't work now. Save your money.

Answer 5

humid air is better because it up the Compression in the Combustion chamber when Petroleum and dry air is mixed you will get Normal combustion however when Petroleum and humid air is mixed in the Combustion chamber the pistion comes up and Compress the mixture that is now denser becaus of the water Vapor it Actually Creates a biger Explosion sound strange but true all the best

Answer 6

Back in the seventies it was all the craze!!

Some motorhome manufacurers even had it pre-installed.
It worked well under high load, low engine speed for pulling long grades up hill.

It does not work well in todays new cars that rev high.
You need a big block engine made from cast iron, with cast iron heads, and long piston stroke.

Answer 7

I think you mean water cooled injectors. People are gonna think you mean having water injected into your cylinders. That of course would be bad. You'd get better performance and better gas mileage if you put a cold air intake kit on your car. They boost horse power and in crease mileage from 5% to 20%

Answer 8

I think it would be a bad idea to inject water into your internally combustion engine becuase it would hydraulock.

Answer 9

No. Those things were pure snake oil. The FTC and consumer Reports both tested several models and found every one to have no or negative effect on engine performance.

Answer 10

Big mistake.Water is the enemy of your bearings.All kinds of crazy ideas surface when gas gets expensive.