Oh Boy - a Hydrogen generator for our Diesels..

[Matt400]

A lot of installers lean out the Oxygen sensor. They say it is to compensate for the extra oxygen produced

I don't think that is the theory, at least from what I have been reading.

The HHO causes a more complete and clean combustion and actually lowers tail pipe emissions. The cleaner more fully combusted exhaust is read by the O2 as a lean condition having less un-burnt fuel.



"IF" this is the case, the ECM will adjust to make the mix more rich so the more fuel added cancels out the HHO benefit. The ones fooling the O2 are doing so to maintain the same A/F as before.

 

[betterthanstock]

I don't think that is the theory, at least from what I have been reading.

The HHO causes a more complete and clean combustion and actually lowers tail pipe emissions. The cleaner more fully combusted exhaust is read by the O2 as a lean condition having less un-burnt fuel.



"IF" this is the case, the ECM will adjust to make the mix more rich so the more fuel added cancels out the HHO benefit. The ones fooling the O2 are doing so to maintain the same A/F as before.

No, a cleaner combustion will cause less oxygen to be present in the exhaust. REmember, right now there is about 2% unburned fuel and 2% unburned oxygen, which then burn up in the catalyst, to make it work. The mixture rapidly fluctuates rich/lean/rich/lean to make the 3 way catalyst to function, and to get any useful reading out of a narrow band oxygen sensor.



So, a more complete combustion uses up more oxygen , and the computer will LEAN out the mixture (cut back on fuel) to restore the 2% oxygen that it expects to see. (It's an oxygen sensor, not a fuel sensor!) Incidentally, this means that a misfiring cylinder will produce more unburned fuel, and more unburned oxygen. The computer will then add even more fuel to reduce the amount of oxygen in the exhaust. Not an ideal situation. Newer vehicles will set a code, but old ones will keep going.

Had the manufacturers, with the epa's blessing, instead decided to use a CO sensor, or and HC sensor, this problem would not occur, but the oxygen sensor was chosen because it matches the functionality of the (inefficient) 3 way catalyst emissions scheme. A more efficient use would be to use lean combustion at cruise, which they do in Europe (and get better mpg and higher NOx emissions) and maybe a urea catalyst to reduce NOx in the tailpipe. So now you know that gassers may be going that direction too (urea), and direct injection, just like diesels.



There are many vaccuum leak devices, sold as economizers, that the EPA has tested. One such device, tested on an old 60's Plymouth, reduced both fuel consumption and emissions at cruise by about 16%, as acknowledged by the EPA itself. There is a site that lists devices tested by epa.

 

[Matt400]

No, a cleaner combustion will cause less oxygen to be present in the exhaust.

Thats assuming all of the left over oxygen is required for the added combustion. And yes I know oxygen is needed for combustion but the invironment is changed with the introduction of HHO, is it not possible this could leave a small % of oxygen unused especially when the HHO has a pure oxygen content?

 

[betterthanstock]

Thats assuming all of the left over oxygen is required for the added combustion. And yes I know oxygen is needed for combustion but the invironment is changed with the introduction of HHO, is it not possible this could leave a small % of oxygen unused especially when the HHO has a pure oxygen content?

I know that hydrogen does something different than hydrocarbons, but most of these devices add so little, like 0. 1% HHO by air volume, which adds 2 H for every O molecule,(thus keeping it stoichiometric, as it wants to recombine back to H2O) to air that already has 21% Oxygen, so that's why I'm skeptical with such low % usage that the savings come from the HHO as opposed to just leaning out combustion (in a gasser). In a diesel, it's already lean, so there's nothing further to lean out.

I have almost built such a device myself to test out, but I first want to see some credible documentation showing a few fill-ups before/after on a diesel, because unless hho has magical powers, the chemistry does not add up. Even if the electricity was supplied for free (which it isn't as it uses up an extra 0. 5 HP to power the electrolyzer) at such a low hho percentage I'm skeptical I would measure any gain.

You've seen my thread about 80% savings with apparently 60% hydrogen, so maybe it saves more than what you put in. But if that percentage was true, then at 0. 6% hydrogen, you would get an improvement of 0. 8% mpg, and that's before subtracting for the 0. 5 hp electrolysis power consumption, which at freeway speeds represents about 1. 5% of the 35 Hp (or so) produced by the engine, or an mpg penalty of 1. 5%. That's why I'm awaiting for some accurate and honest test, not "I topped it off after 35 miles and got this 40% improvement" that you see all over the net.

 

[highgear]

i think that the hho gas would work better if it was added to the intake horn just before it enters the engine. the ctd doesnt show any turbo boost most of the time,and adding a home made plastic valve that under turbo pressure buildup would close the hho gas so that the boost would not blow the hho gas backwardjust an idea watch your boost guage and see if you can drive without boost most of the time ????