The engine runs on water injection

You may have already heard about the (rather controversial) Pantone system, which uses water in the engine to reduce fuel consumption and environmental pollution. If the latter only applies to certain “do-it-yourselfers”, be aware that big brands are beginning to study this issue, even if we cannot speak strictly about the Pantone system (more details here).

Indeed, the system is a little easier to understand here, even if it remains fairly similar in general terms.

Note that we can also make a connection with nitrous oxide (which some call nitro), which this time is to pressurize the engine with oxygen, see here for more information.

How does it work?

I can assure you that the principle of operation of a water injection engine is quite simple to learn.

First of all, you need to understand a few basics, such as the fact that an engine performs best when cool air is supplied to it. Indeed, cold air takes up less space than hot air, so we can put more in the combustion chambers when it is cold (more oxidant = more combustion). It's pretty much the same principle when you blow a fire to take advantage of it).

You will understand, the goal here is to cool the air entering the engine even more.

Here, in blue intake manifold

The fact is that air usually enters the engine at a fairly low temperature, so why install a system that cools it even more? Well, it should be remembered that most modern engines use turbocharging ... And whoever says that turbo, says that pressurized air enters the intake (turbo works here). And aspiring physicists will quickly figure out that compressed air = heat (this is also the compression / expansion principle that is used to control air conditioning).

In short, any compressed gas tends to heat up. So, in the case of a turbo engine, the latter gets quite hot when you are at high rpm (the pressure of the turbocharger increases). And despite having an intercooler / heat exchanger to cool the air coming from the turbo, the air is still pretty hot!

Here is one of the intake valves that opens to let air in.

Thus, the goal will be to cool the air en water injection in the form of microdroplets at the inlet (just before air enters the cylinders). This method of operation also resembles indirect injection, which also consists of injecting gasoline at the intake level rather than into the engine.

So understand that this water injection is not constant, it is beneficial when the air entering the inlet is hot enough.

Thus, the system is suitable for both gasoline and diesel engines having the same problem.

BMW on the move

This principle was used in the M4 and 1i prototypes of the 118-cylinder Series 3.

According to the brand and after many tests, there will be an increase 10% power for 8% less consumption! All thanks to intake cooling up to 25%.

However, it should be noted that the savings

the more important the more you use the engine

In this way, it helps to limit the overspending of gasoline caused by dynamic driving (diesel engines use less fuel in a sharp, proportional expression). So those who drive sporty will benefit even more from the savings. BMW points 8% in driving

"Ordinary"

et close to 30% in driving

playful

(As I explained earlier, the system is mainly used when the intake air gets hot, and this is when you climb the towers).

► 2015 BMW M4 Safety Car - Engine (Water Injection)

Other benefits?

This system will provide other benefits:

• The compression ratio can be increased, which improves performance.
• The ignition (petrol) can be ignited earlier, which contributes to fuel consumption.
• This system will allow the use of lower quality fuels, which would be an advantage in some countries.

On the other hand, I see only one: the system increases the number of parts that make up the engine. Therefore, the reliability is potentially less good (the more complex the object, the higher the probability of its failure).

If you have any other thoughts to complete the article, feel free to do so at the bottom of the page!