Vacuum intake manifold or Air intake?

[dennis13030]

What do you guys mean when you say butterfly?

The butterfly(aka Throttle body).
http://fc3spro.com/TECH/HOWTO/TBM/tb01.jpg

It's the valve that opens more when the accelerator is pressed.

[ridelong]

SmoothieV,
The butterfly is a circular metal plate that mostly blocks off the intake at idle. When the throttle (gas peddle) is pressed, it pivots to open the airway.

[SmoothieV]

Oh ok, gotcha! Thanks guys!

[dennyk159]

Countryboy18,

Put a generator in my friends Honda this afternoon. He thought that putting the input downstream of the butterfly, like you, would work better.

The longer I thought about it the more it made sense.

We put it in and, HOLY CRAP, the same generator I used was generating 5 times the gas I was.

I bow to your thought processes. Even a Mensan screws up sometimes.

Can't wait to see what his mpg increase is.

ridelong
At lower pressures, water boils at lower temperatures. You can boil water at room temperature if the under enough vacuum. I also believe you make more HHO under vacuum as well, but at the same time, it may have water vapor in it. Just be careful assuming everything coming from the generator is HHO if under a vacuum, especially if the engine was at idle when vacuum is greatest. My 2 cents.

[Stratous]

ridelong
At lower pressures, water boils at lower temperatures. You can boil water at room temperature if the under enough vacuum. I also believe you make more HHO under vacuum as well, but at the same time, it may have water vapor in it. Just be careful assuming everything coming from the generator is HHO if under a vacuum, especially if the engine was at idle when vacuum is greatest. My 2 cents.

He is correct, water will boil if put under vacuum. I too fell prey to the assumption that HHO generation increased under vacuum. It may increase, but its not what you see. It is difficult to say for sure as most of us back yard mechanics cant seperate water vapor/hydrogen/oxygen to actually perform the test.
Here is the lowered boiling point of water in a vacuum
Water will boil at 120°F when in a vacuum of 26in of mercury

[Omega]

He is correct, water will boil if put under vacuum. I too fell prey to the assumption that HHO generation increased under vacuum. It may increase, but its not what you see. It is difficult to say for sure as most of us back yard mechanics cant seperate water vapor/hydrogen/oxygen to actually perform the test.
Here is the lowered boiling point of water in a vacuum
Water will boil at 120°F when in a vacuum of 26in of mercury

So are you running your HHO to the intake instead of a vacuum line???

I'm currently hooked up to a vacuum line and it's very difficult to keep the generator and bubbler "under control". I assume it would be less "violent" to run the HHO to the intake, my concern would be influencing the MAP sensor, since I can't get a feed in downstream of it.

[Dewayne]

I saw a video today where a guy is using 2 HHO inputs to the engine.

He put a "T" fitting in the HHO line. One is going to the manifold vacuum and the other in going to the air intake. He puts a check valve into each of the line, this way which ever line has the greatest vacuum the HHO is pulled through that line.

This makes some sense to me. As the manifold vacuum drops the air intake vacuum increases.

[Omega]

I saw a video today where a guy is using 2 HHO inputs to the engine.

He put a "T" fitting in the HHO line. One is going to the manifold vacuum and the other in going to the air intake. He puts a check valve into each of the line, this way which ever line has the greatest vacuum the HHO is pulled through that line.

This makes some sense to me. As the manifold vacuum drops the air intake vacuum increases.

Seems to me that all that type of setup would do is average out the vacuum to the enclosure. The stronger vacuum would pull the weaker vacuum backwards and eventually reach equilibrium.

I'm trying the HHO to the air intake now. I started with the HHO going to a vacuum line (PCV valve hose) and it would suck my bubbler dry in a short time, even with a check valve between the HHO enclosure and the bubbler. I test drove my car tonight with the feed to the air intake and it seems much better. A hundred miles or so will tell the story.

[Q-Hack!]

On a Carbuated engine, the buterfly is inside each of the barrels of the carbuator. Its the roundish metal plate that is mounted on (and rotates around) a pin. At idle this plate will close off the opening letting only a little air into the engine... at full throtle it is wide open.

Most fuel enjected cars also have some sort of butterfly as well. Usually it is located at the Intake manifold, but not always.

[Stratous]

So are you running your HHO to the intake instead of a vacuum line???

I'm currently hooked up to a vacuum line and it's very difficult to keep the generator and bubbler "under control". I assume it would be less "violent" to run the HHO to the intake, my concern would be influencing the MAP sensor, since I can't get a feed in downstream of it.

Yes, I have my generator gas exit just past the air box. I have a diesel, so dont have the vacuum options.

When running the generator on vacuum with a check valve between the bubbler, you need to make sure your generator has a small leak or something. The reason is as follows. The greatest vacuum is created at engine idle. Lets say your engine produces 20Hg at idle. Your hho gen is now at 20Hg as well, then when you step on the gas pedal the engine vacuum drops below 20Hg. That will cause the check valve to close which will not allow the HHO gen to equalize the vacuum pressure because the hho gen vacuum is greater than the engine vacuum. This will especialy become a problem in city driving.