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View Full Version : Vacuum intake manifold or Air intake?



Gregoryn
07-16-2008, 03:03 PM
Hello! I am going to install this generator:

http://img398.imageshack.us/img398/8747/generator1fm3.th.png (http://img398.imageshack.us/my.php?image=generator1fm3.png)

http://img185.imageshack.us/img185/3654/generatorbubblernv5.th.png (http://img185.imageshack.us/my.php?image=generatorbubblernv5.png)

manufacturer says that the production is +2 l/m at high amperage

I plan to use a smaller amount of electrolyte because i dont need so much production. My engine is only 1.3 Lit :)

My questioning is this: i need to plug the generator to vacuum intake manifold or to Air intake? Or both?
I will appreciate if someone explains the advantages and disadvantages of this methods.

Thank you!

countryboy18
07-16-2008, 03:35 PM
nice cell!!! people connect there cells to vacuum because it increases there prouction. it is ok the connect it to the air intake since production is not a problem with your cell. that a cool idea with the bubbler acting as a reserve and a cooling container. do you mind saying how much you paid for it or how much it cost you.

Gregoryn
07-16-2008, 04:10 PM
nice cell!!! people connect there cells to vacuum because it increases there prouction. it is ok the connect it to the air intake since production is not a problem with your cell. that a cool idea with the bubbler acting as a reserve and a cooling container. do you mind saying how much you paid for it or how much it cost you.

Thank you! I paid about 200 USD + shipping cost to Greece (for 1 cell, not the pair you see in photos) :o
People says that i will also need an ''original'' bubbler and i think that i will apply this advice.

ridelong
07-16-2008, 05:39 PM
Put the tube UPSTREAM of the butterfly, between the air filter and the butterfly. Preferably as close to the butterfly as possible.

If you put it past the butterfly, you will have maximum vacuum at idle and minimum vacuum at full throttle, exactly opposite of what you want

countryboy18
07-16-2008, 05:41 PM
why is there less vacuum at faster speeds

cougar gt-e
07-17-2008, 12:22 AM
why is there less vacuum at faster speeds

I think he is meaning that if you put the line under the throttle you will have manifold vacuum, when you operate at wide open throttle the manifold vacuum will be close to zero.

If you use a "timed vacuum port" that is above the throttle, the vacuum goes up due to venturi effect and higher air flow rates make more vacuum.

That is based on carburators, I don't know how it relates to fuel injection systems. It may not ! Carbs I get, FI --- not so much.

countryboy18
07-17-2008, 10:47 AM
you are right less vacuum at full throttle but at full throttle the car is well with a stick shift car you get better mpg in 5 or 6 gear so you realy dont need more hho because the car is more effecient at faster speed. you need strong vacuum in city driving.

this is what my brain is telling me i could be wrong but that is part of life.

ridelong
07-17-2008, 12:30 PM
countryboy18,

What cougar gt-e said is what I was was refering to. All of the reading I've done says to put it just before the butterfly.

I've been running hho for about 4 months now, input the gas just before the butterfly. I got 37.5% increase, from 22.4 to 30.8 mpg using a quart generator. Just installed a 1/2 gallon hho, will report at fillup.

2003 ranger 2.3 liter 5 speed standard.

ridelong
07-22-2008, 08:11 PM
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.

SmoothieV
07-23-2008, 07:22 PM
What do you guys mean when you say butterfly?

dennis13030
07-24-2008, 12:34 AM
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
07-24-2008, 07:16 AM
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
07-24-2008, 08:06 AM
Oh ok, gotcha! Thanks guys!

dennyk159
07-26-2008, 11:04 PM
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
07-26-2008, 11:13 PM
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
07-28-2008, 12:47 AM
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
07-28-2008, 01:06 AM
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
07-29-2008, 12:33 AM
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!
07-29-2008, 02:25 AM
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
07-29-2008, 08:44 AM
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.

Omega
07-29-2008, 02:22 PM
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.

That's why I've changed from a vacuum line to the air intake for putting the HHO into the motor. I live in the mountains a coast a lot, so the generator saw lots of max. vacuum time. It's necessary to leave some air space in the top of the generator which creates more problems with a significant vacuum "volume" that is very powerful. My generator was completely sealed with no leaks and the problems were numerous.

The biggest problem with the vacuum line hookup is the lower boiling point of water at a vacuum. A running temperature of 160 or 170F becomes boiling at a certain vacuum level. So "thermal runaway" can occur under a vacuum when it wouldn't if hooked up to the air intake.

The vacuum effect in the bubbler was an issue I couldn't overcome. Water would get sucked out no matter what I did. The advantages of hooking up to a vacuum line are far outweighed by the disadvantages, IMO.

With my HHO input going to the air intake, I have no loss of water out of the bubbler and no problem leaving an adequate air space in the generator. The car actually seems to run better with the current hookup, too.

HHOhoper
07-29-2008, 04:18 PM
I agree. I've investigated the vacuum from the air intake and I was surprised that on both of my cars the hose still produced enough vacuum that I'm convinced it's still sucking a considerable amount of gas without putting a huge vacuum pressure on the cell.

RMForbes
08-01-2008, 02:27 PM
On my car I used both. I have a line that T's into the crankcase vent hose that enters the intake just before the butterfly valve, and ran a line into a main vacuum port. I added a valve to the vacuum line so I could reduce the vacuum to the cell at idle to the same as the cell was producing. This is easier than it sounds because when the cell is under vacuum the water level rises, so I just watched the water level in the cell and the bubbler adjusting to the max gas output without rising the cell water level. Both lines have one way check valves inline so when the engine vacuum drops that check valve closes and the gas from the cell flowes to the other line.

Stratous
08-01-2008, 02:48 PM
Currently, I have built 5 cells. I have found that a large vacuum will slowly cause the container seals to leak. The last cell sat for 6 days with no leaks, then ran under vacuum for 1 day. The next moring after sitting unused for the night, I discoverd a leak. I am certain that the vacuum caused the leak.

countryboy18
08-01-2008, 08:10 PM
if the cell is under vacuum then the water will boil at a lower temp. so what is the problem with the water boiling. if the temp is the same weather under vacuum and at normal presure then what is the problem with the water boiling. another thing you can do is use antifreeze insted of water or do a mix of the two to reduce the chance of it boiling.