Others are looking too. I'm not much "into" this but thought maybe others might find this interesting?

Scientists at Penn State and the Virginia Commonwealth University have discovered a way to produce hydrogen by exposing selected clusters of aluminum atoms to water. The findings are important because they demonstrate that it is the geometries of these aluminum clusters, rather than solely their electronic properties, that govern the proximity of the clusters' exposed active sites.

The proximity of the clusters' exposed sites plays an important role in affecting the clusters' reactions with water. The team's findings have been published in the Jan. 23 issue of the journal Science.

Read the full story on Live: http://live.psu.edu/story/37146/nw4

Wow - LumenLab has evolved quite a bit since I was here last.

Looks like this thread has been stalled for a while, but as I was reading it I was thinking about the same basic point that SupraGuy made. I don't buy the idea that injecting the HHO would result in "extra" O2 in the exhaust. If the hydrogen is combusting and the mixture is promoting a more complete burn, then you would have to have LESS O2 in the exhaust. O2 in the exhaust can be seen as a result of incomplete combustion - because we know that there are various unburned hydrocarbons in the exhaust (at least upstream of the catalytic convertor). Getting those unburned HC's to react with the available O2 is what the cat does, and it's what HHO proponents claim the HHO does, but in the cylinder.

So for the claims about HHO injection to make any sense there would have to be less O2 in the exhaust, not more.

My gut feel about the supposedly good results some folks are seeing is that it's a combination of driver behavior (you spend more time at WOT when you mod a vehicle for power, and you spend more time driving conservatively when you mod it for fuel consumption) and the effect of leaning out the fuel mixture by messing with the signal from the O2 sensor. The results I'd be most interested in seeing would be an engine on a dyno calculating brake-specific fuel consumption.


I also have to say that the remark about success depending on the intake manifold design seems off-base. That gas is going to dissipate into the airstream very quickly, and the idea that the manifold design could result in different concentrations being delivered to different cylinders is very hard for me to accept.

Anyhow, it's an interesting subject and I know that SJ is taking a very methodical approach. I'm looking forward to seeing more info about this.

Possibly one of the better explanations I have seen for O2 sensors behavior...

How does an O2 sensor work?

An Oxygen sensor is a chemical generator. It is constantly making
a comparison between the Oxygen inside the exhaust manifold and air
outside the engine. If this comparison shows little or no
Oxygen in the exhaust manifold, a voltage is generated. The
output of the sensor is usually between 0 and 1.1 volts. All
spark combustion engines need the proper air fuel ratio to
operate correctly. For gasoline this is 14.7 parts of air to one
part of fuel. When the engine has more fuel than needed, all
available Oxygen is consumed in the cylinder and gasses leaving
through the exhaust contain almost no Oxygen. This sends out a
voltage greater than 0.45 volts. If the engine is running lean,
all fuel is burned, and the extra Oxygen leaves the cylinder and
flows into the exhaust. In this case, the sensor voltage goes
lower than 0.45 volts. Usually the output range seen seen is
0.2 to 0.7 volts.

The sensor does not begin to generate it's full output until it
reaches about 600 degrees F. Prior to this time the sensor is
not conductive. It is as if the circuit between the sensor and
computer is not complete. The mid point is about 0.45 volts.
This is neither rich nor lean. A fully warm O2 sensor *will not
spend any time at 0.45 volts*. In many cars, the computer sends
out a bias voltage of 0.45 through the O2 sensor wire. If the
sensor is not warm, or if the circuit is not complete, the computer
picks up a steady 0.45 volts. Since the computer knows this is
an "illegal" value, it judges the sensor to not be ready. It
remains in open loop operation, and uses all sensors except the
O2 to determine fuel delivery. Any time an engine is operated
in open loop, it runs somewhat rich and makes more exhaust
emissions. This translates into lost power, poor fuel economy
and air pollution.

The O2 sensor is constantly in a state of transition between high
and low voltage. Manfucturers call this crossing of the 0.45
volt mark O2 cross counts. The higher the number of O2 cross
counts, the better the sensor and other parts of the computer
control system are working. It is important to remember that the
O2 sensor is comparing the amount of Oxygen inside and outside
the engine. If the outside of the sensor should become blocked,
or coated with oil, sound insulation, undercoating or antifreeze,
(among other things), this comparison is not possible.

Oxidizing aluminum, as with most metals is not the challenge. The challenge is reducing those metals (i.e. removing oxygen) in an economical fashion. Under the right conditions most metals will react with water to take up its oxygen and produce hydrogen. The hydrogen can then theoretically be used in a fuel cell. But then what do you do with the metal that has been oxidized. Well, you have to reduce it or remove its oxygen to make it reactive again. That takes energy. Oftentimes, the life cycle for the oxidation-recycling-reduction of metals to produce hydrogen for energy production is impractical.