Do-it-yourself damp air device

[Emporator Member Find all posts View Profile Close Emporator]

Hello all!

For those who don't already know, I have a bit of a "thing" for water injection. Not only water injection, but also on the whole idea of water and such and its' effects on engines. I had an idea whilst travelling through some fog one day. I thought it would be great if you could reproduce the fog effect on demand for an internal combustion engine. After much tinkering, I believe I have the answer! I've built a small device that provides "damp air" to an engine on demand. There's no parts to wear out and it works perfectly. I've tried it on two cars with promising results.

So, what is this miracle device I hear you ask? Ponder no further! The device is an ordinary oil catch can that one can purchase at any automotive store. The one I selected has a beautiful chrome finish for looks. I've taken one of the inlet barbs and put a hose that runs through the barb all the way to the bottom of the catch can. At the bottom of the hose (which is inside the can) I've put an aquarium air stone. This air stone is to be covered with water. Then, connect the other hose barb to the inlet manifold of your engine. By low atmospheric pressure, air will be drawn into the catch can and through the aquarium air stone, producing lots of bubbles and thus producing damp air. By doing this you will have re-created a foggy day! Here's a link to something similar that offers a better explanation as well as a photo of a similar device:

Mother Earth Alcohol Fuel: Ron Novak's Do-It-Yourself Water Injection System

Looks like my original idea isn't as original as I would have you believe! It's amazing though isn't it how two people can come up with something that is almost identical yet are separated by a huge distance. I was kind of disappointed to learn someone came up with this idea as well - not to mention before me!

[TroyH Senior Member Find all posts View Profile Close TroyH]

Re: Do-it-yourself damp air device

I'm interested in why they say the unit bubbles more during idle, than it does at full throttle. I'd have thought that is would be the exact opposite.

Have you ever had a look to check this emporator?

The alcohol in the solution doesn't only act to prevent it freezing in cold water, but it lowers the vapour pressure of the solution, so you are more likely to get vapour.

[Qwarla Senior Member Find all posts View Profile Close Qwarla]

Re: Do-it-yourself damp air device

Troy you are thinking along the wrong track. The unit produces bubbles by manifold pressure. At idle the throttle butterfly is closed so the pressure is at it's lowest. At full throttle the butterfly is wide open so the manifold pressure is very close to atmospheric pressure so very few bubbles are produced.
This will only happen with a petrol engine as most diesels have unrestricted intake, and as such there is no substantle pressure drop in the manifold.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Do-it-yourself damp air device

If one had a Turbo Diiesel, one could use manifold Pressure to bubble air into the water, providing a mist into the air intake to the Turbo. At idle, water injection would cease, as there would be no boost to provide the bubbles.

I may try that out once my OM 617 952 is instaled.

[TroyH Senior Member Find all posts View Profile Close TroyH]

Re: Do-it-yourself damp air device

Ahh I see. I didn't notice they had set it up on the engine side of the throttle.

I'm thinking one should be able to alternatively connect it on the other side of the throttle and get the opposite effect. This could be compounded by having the intake hose (the one connected directly to the air stone) in the high pressure region poking out of the bumper.

Any idea if it would be of more benefit at higher rpm? My guess is there wouldn't be enough water/ethanol for the amount of air going into the engine at WOT.

So the major effects are a) cooling the intake charge b) providing water into the intake stream that can contribute to gas expansion in the cylinder and c) extra combustible material (ethanol)
anything else?

[Emporator Member Find all posts View Profile Close Emporator]

Re: Do-it-yourself damp air device

Hello TroyH!

It is indeed correct - on a petrol engine the bubbling will be more active at idle than at any stage of throttle. Bubbling will be most furious at maximum inches of mercury, ie when the engine is coming down a hill with no acceleration.

On a diesel or a turbo-diesel it's best to have the device before the turbocharger so that there will always be suction, so to speak.

[TroyH Senior Member Find all posts View Profile Close TroyH]

Re: Do-it-yourself damp air device

out of curiosity, where do you put the "intake" of the air hose going into the air stone?

[Emporator Member Find all posts View Profile Close Emporator]

Re: Do-it-yourself damp air device

Hello TroyH!

The piece of tubing that goes into the air stone is secured inside the hose barb. It just breathes atmosphere - what I mean to say is, air from the atmosphere enters the tubing, and then passes through the airstone.

[TroyH Senior Member Find all posts View Profile Close TroyH]

Re: Do-it-yourself damp air device

aah ok, so it just sits inside the engine bay?

I was just thinking that if it was positioned in the high pressure region at the front of the vehicle, it might work a bit better once you get rolling.

[Emporator Member Find all posts View Profile Close Emporator]

Re: Do-it-yourself damp air device

Hello again TroyH!

Yep, the device (I haven't even got a name for it yet!) just sits in the engine bay. I guess that if you were to fit a small scoop that might help somewhat if it was positioned correctly. Otherwise, I'd think the gain would be negligible.

[Qwarla Senior Member Find all posts View Profile Close Qwarla]

Re: Do-it-yourself damp air device

Just looking again at the design on the Mother Earth website. It is fitted to a petrol carburetored engine. It feeds in through an eigth inch hose barb. The amount of wet air passing through an eigth inch hose barb will really be bugger all, compared to what passes directly down the throat of the carburetor. So I would think the effect would be very small.

Now to use this on a turbo diesel, you would reverse the connections as Troy is thinking. Take bost pressure and feed into the airstone, then take the wet air and feed this back into the intake side of the turbo.
One would have to ensure the bottle used can handle your maximum bost pressure. That shouldn't be a problem for a PET coke bottle as they can handle over 100 PSI before they burst.

[Emporator Member Find all posts View Profile Close Emporator]

Re: Do-it-yourself damp air device

Hello Qwarla!

I like the idea of connecting the catch can to the turbocharger. One would have to make it watertight though, as surely the positive pressure would force water out of the can. Great idea though!

[Guest Close David]

Re: Do-it-yourself damp air device

It is fitted to a petrol carburetored engine. It feeds in through an eigth inch hose barb. The amount of wet air passing through an eigth inch hose barb will really be bugger all, compared to what passes directly down the throat of the carburetor.

I agree with what Qwarla is saying here and his earlier comment about the drop in manifold vaccum in a diesel compared to a petrol engine is also correct. I believe on a diesel, this setup would be ineffective and a water injection system would have much more positive results.

One flaw I find in the ME claims is that this system would save fuel.A properly working water injection system will cause an engine to use MORE fuel, not less. Water does not burn or do anything other than to increase an engines ability to burn more fuel through creating a denser air charge.

In their article, they specify they are using a water /alchol mix so they are really adding another fuel source to the engine. Did they take this amount of fuel into their fuel saving calculations? Of course not! If the did they would find the engine uses the same or more fuel than before and anything else is wishful thinking or a difference in driving technique.

This device is a poor mans water injection system and I believe the mimimal water it would use would have a corresponding minimal effect on the engine.
For Diesel engines I believe it would be much better to spend a few more bucks on a pump assisted water injection system and squirt some significant water in there.

[Emporator Member Find all posts View Profile Close Emporator]

Re: Do-it-yourself damp air device

Hi David!

I'm afraid I have to agree with you - it's a poor man's water injection device. Still, it does seem to work ok though. Nowhere near as good as a proper water injection system mind you!

[Qwarla Senior Member Find all posts View Profile Close Qwarla]

Re: Do-it-yourself damp air device

Hello David. I think the ME site may be saying that for 'normal' driving you can save fuel. I am sure you are correct saying it can make an engine use more fuel, at wide open throttle. More fuel=more power output.

One thing comes to mind though. One of my brothers used to have a car computer, back about the late 70's, that does much like what is in some cars these days. Gives you current fuel consumption, trip distance and fuel burn and remaining fuel in tank.

He would measure more economy when driving in foggy conditions. Now was this because of the excessivly wet air, or the fact that when visibility is poor we tend to drive a bit slower and in doing so increase economy?