Have any of you ever messed around with water injection for added power. From what I have seen so far (and that isn't much) I can probably get an additional 15 hp. or 15% and about 25% better fuel efficiency. But have any others done this and have numbers for what works as far as kits and have HP/MPG numbers to throw around. Preferably for a 12A stock.

 

it wouldnt do jack really on a stock 12a, people use it on forced induction to counter the effects of heated air via a turbocharger..

 

Man you should have done a search. Actually it all depends on the type of atmosphere where you live. If it's really dry w/ low relative humidity, the you could benefit from water injection. The kits offered come with different size jets for your type of application, and tuning is always optimal on a dyno. (my personal advice). It's quite common amongst RV owners and they benefit from the added MPG. Forced induction, gains it's benefit from the added decrease in temp inside the combustion chamber. And becuase of the systems' high heat dissipative qualities it also keeps carbon from building up in your enigne. Most manufacturers claim that afer 1,000 miles of use you should have considerable less amounts of carbon. It's old technology. Goes back to the Air Force using it, in the P-51 mustangs during WWII

 

Makes no sense physics wise. Water is less dense than air (alot) so water injections in a combustion engine is actually robing of hp. Only thing its good for is cleaning, and on a rotory the chambers move so fast it wouldnt have time to theoretically give hp. Air force also used on jet engines but that is a different design of hp, more for thrust, and only one engine was ever produced and utilized using water injection, but it was ******* cool.

Steve Shulz USAF Jet Engine Mechanic.

 

well it has to make sense physics wise we just havent figured out why. Physics is the study of how things happen in the real world. If it produces more HP then it produces more hrsepower, and there is a physical explainaton for it.
The Neanderthal Astrophysics Student

 

You must not be a very good mechanic.

Water is MORE dense than air by a LOT. Thats why water dosen't compress and breaks stuff when it finds it self on top of pistons and between rotors and housings. The theroy behind water injection in a turbo/supercharged motor is that it will reduce the intake temp after it has become compressed, by absorbing and retaining heat. water is one of the best liquid mediums for heat transfer known to man. When water is introduced into the intake track it imediatly begins to remove heat from the compressed intake air. and viola lower intake temps. the cooler the water the cooler the air.

The same effect is true on a naturally aspperated motor, but a N/A benifits more from the inability of water to compress, because it is MORE DENSE THAN AIR, it takes up space that could be filled by air, effectivly increasing the compression ratio. But don't go run out and hook-up a culligan water cooler to carb or throttle body there is more of sceince to it than that.

Ryan Shook Mechanical Engineering student

 

What type of pump do you use to meter the flow? I assume flow must increase with boost? One guy I talked to said use a windshield washer pump.

 

Water is less dense than air (alot)

man check your chemistry. Maybe in some third world countries, but in this one and many other's like it. water aka H2O is FAR more dense than pretty much ANY gas. that includes the air in the atmosphere which is comprised of several. Sorry friend but you are the weakes link
Johann Gomez USAF PLUMBER

 

Yes flow should increase with boost, and I have herd of people using windsheild washer pumps, fuel pumps, but nothing you will beable to peice together will have the ability to increase water flow with boost pressure. If you must peice it together try nitrous jets for injecting, and a windshield washer pump.

For those of you considering this option have you considered setting up an intercooler sprayer. You get the same benifits but you don't have worry about hydro-locking your motor, which can be done with little effort.

Ryan

 

OK Ryan Shook Mechanical Engineering student, if you introduce water into the chamber effectively reducing the space then you get more compression. Question, how does a combustion chamber produce power? Well if you forgot (or havent learned that yet, being a student and all) Answer, by mixing fuel and air (last time I check fuel and water dont mix) and the best fuel and air mix is? Any guesses? well its 15:1; RX-7's by the way are running at 9.1:1, so if you introduce water, effectively reducing space therefore reducing the fuel to air ratio what are you left with? A rich running (but cool)engine. Where is the HP now? If you theory is correct (which it isnt) then why does a car run so shity if you get water in your gas tank? (read above again if you didnt get it) I bet the people who make the gas adative Heat would just freak out if the populous heard what you had to say.....

 

One more for you, mr student, 1 gallon of water weighs approx 6.9 lbs. How much air would it take to weigh 6.9 lbs? So is water more dense? No its just condensed air. This excerp taken from USA Today entitle "Understanding Air Density"

Humidity and air density
Most people who haven't studied physics or chemistry find it hard to believe that humid air is lighter, or less dense, than dry air. How can the air become lighter if we add water vapor to it?

Scientists have known this for a long time. The first was Isaac Newton, who stated that humid air is less dense than dry air in 1717 in his book, Optics. But, other scientists didn't generally understand this until later in that century.

To see why humid air is less dense than dry air, we need to turn to one of the laws of nature the Italian physicist Amadeo Avogadro discovered in the early 1800s. In simple terms, he found that a fixed volume of gas, say one cubic meter, at the same temperature and pressure, would always have the same number of molecules no matter what gas is in the container. Most beginning chemistry books explain how this works.

Imagine a cubic foot of perfectly dry air. It contains about 78% nitrogen molecules, which each have an atomic weight of 28. Another 21% of the air is oxygen, with each molecule having an atomic weight of 32. The final one percent is a mixture of other gases, which we won't worry about. Molecules are free to move in and out of our cubic foot of air. What Avogadro discovered leads us to conclude that if we added water vapor molecules to our cubic foot of air, some of the nitrogen and oxygen molecules would leave — remember, the total number of molecules in our cubic foot of air stays the same. The water molecules that replace nitrogen or oxygen have an atomic weight of 18. This is lighter than both nitrogen and oxygen. In other words, replacing nitrogen and oxygen with water vapor decreases the weight of the air in the cubic foot; that is, it's density decreases.

Pay attention to the last sentence!

 

you all need to re think your theories especially you plumber guy! You see those things flying over your head and wonder why they dont fall? Air my friend dense air, air, air, air. Not water!

 

Where are your replies now???? Dont talk **** unless your ready to back it up. One free lesson for you mr Mekanikal Enguneerin Student, Keep in the books! youve got a long way to go. And to think USA Today Weather was all it took to show the light, I didnt even bust out the Barometric pressure card either.....

 

Mr Steve Shultz,

The term used to describe "the best fuel and air mix" is called a stoichiometric ratio. For petrolium based fuel, such as the fuel that everybody uses, it is 14.7:1. A rotory engine tends to produce the most power on a ratio of approx 13:1, just like a piston motor. If you try running your car at a ratio of 9.1:1 you would be spewing black smoke, plants and trees would fall by the wayside, and you would get, if you are lucky, about 80 miles to the tank.

Injecting water vapor into the air stream can not physicaly change the ratio of fuel to air. Water, unlike petroleum based fuel, does not mix with air when atomized. When you add atomized water to a mixture of fuel and air, it is like adding ice cubes to your soda.

Oh yea and the reason your car runs like **** when put water in you gas take instead of fuel, is because water doesn't burn, or did the Air Force forget to mention that to you.

You know there is a place called a liberary near you, it it were they keep all of the neat books, try visiting it one of these days. That way in the future you can stop giving good mechanics a bad name.

 

I just wanted to know what kind of pump to use.

 

I am wanting to use this option on a carburated suck thru turbo set up, so an intercooler isn't going to be part of the system.

 

How many contra-dick-tions can I count in your reply. You sir, give mechanics and scholars a bad name. Did you read the post about density? You can't change physics no matter how much you whine, can I get you some cheese? Maybe YOU should go to the library and get a book on Cryonomics (I mean contradictions) and get a spelling book while your at it.

Enough said, somebody do it and report please... I should have been from Missouri, but I'm betting you're all full of ****.

 

You do know that plagiarism is illegal, don't you.

All of what you said was take from that artical. Do you have the ability to proccess incoming information? Or, are you of those guys that just records everything and plays it back because you think it makes yourself look intellegent.

 

Did I not say where it was taken from, giving USA Today credit not once but twice? (read again the definition of plagiarism, I looked at dictionary.com, maybe you should hang out there more ofter) I tried to speak in terms but with all the crap people were saying I used something written to back up my point. And for the record "No, I dont record everything and play it back to look intelligent, I have you to thank for that............" Thanks.

 

How much boost are you going to be running?

 

Why don't we keep this on topic. Lets not have a clash of wit between you two. I finally find some people talking about a subject I can't get anyone to talk about and it turns into a **** fight. Bullshit!

 

I want to run maybe 10psi of boost on a set of the old 74-78 13b rotors. They are 9:2:1 rotors.

 

Sir, you are correct. I appologize for Steve Shulz and my adolesent behavor.

 

Start a new thread, it is too distracting to get what your looking for. moremazda is still wiping his nose. And no need to apologize for me, your ignorance still proceedes you no matter what you say.

 

Water injection is used by several members on this forum. "RICE" (Peter) has used water injection to compliment a system that makes over 500hp at 15psi. Try doing a forum search on water injection.

hope this helps, Wayne.