[electronFarmer]

OK, I have read the entire thread... I agree Mythbusters Suck. I have seen some, but not every episode. Some were good but some were awful science. The 200 MPG episode truly sucked with them simply buying a carb off the internet. They made no mention whatsoever of Charles Pogue and his work (US patents # 1,750,354, # 1,997,497, and the most often cited # 2,026,798) nor did they make use of exhaust or radiator heat to preheat the gasoline. You can not bust a myth unless you build it the way it was claimed to work, try it and then find it does not work.
Then they played around with a hydrogen generator, using electrolysis, that is electricity from the car's 12 volt system through plates submerged in water. This breaks the water into it's constituents of hydrogen and oxygen, 2 to 1. This did not show any gain to the mythbusters crew so they acquired a bottle of pure hydrogen and fed it directly into the carb. Yes the engine ran on that. Oh but then they had a fire. Doesn't that make for good video footage to tell Joe Sixpack not to try this at home...
A friend of mine, Mike Campbell (since passed away) and I also played with hydrogen. The electrolyte we chose was NaSO4, that's Sodium Sulfate. It is neither acid nor alkaline. We did not use table salt, sodium chloride, because we did not want to generate chlorine gas. We did not use sodium hydroxide or potassium hydroxide as these are strong alkalines. We did not use hydrochloric acid again because of the chlorine gas generation, even though this would also generate more hydrogen. Nor did we use sulfuric acid. We did not want the acids to "eat" our metal plates. Our plates were eaten anyway, but more on that later. We "made" our electrolyte by combining, slowly, sulfuric acid with sodium hydroxide (lye) until our pH meter gave a neutral reading. This MUST be done in a plastic container, the type that sulfuric acid comes in. Even then this mixing evolves heat and altered the shape our our plastic container. Later I found out that you can just buy Sodium sulfate as a powder. I have a bottle of it now. This electrolyte is not consumed in the reaction. The hydroxide of the sodium hydroxide or potassium hydroxide IS consumed. The chloride of sodium chloride or hydrochloric acid IS consumed.
We kept a notebook but I do not have it. But if my memory serves me correctly we started with 1/2 gram of the (powder equivalent) sodium sulfate to 1.5 liters of pure water. We built several different electrolysis "chambers" but each of them held about 1.5 liters. The electrolyte serves as the charge carrier between the plates and, as I mentioned, is not, or should not be consumed by the reaction.
We tried several different metals in our plates, aluminum, titanium (very high electrical resistance and expensive), settling on stainless steel, 318, but not switch plate covers. Only much later did I hear about the problem with the chromium, part of the stainless "recipe" showing up as a problem in the water solution.
No attempt was made to separate the hydrogen from the oxygen. That means the gas produce in the chamber is VERY explosive. Separating the gasses would be made in the design, by separating the positive and negative plates by some distance and placing a physical barrier from the top of the chamber down into the water level for some distance. The bubbles off of one set of plates would then be kept separate from the bubbles off the other set of plates. But then the electricity would have to travel further through the electrolyte charge carriers and increase the resistance.
We used a lawn mower engine, vertical shaft Briggs and Stratton, mounted on a test stand. We mounted a fairly heavy, for it's size of 5 inch, cast iron pulley to act as a flywheel and drive an automobile alternator with a belt. The electricity output of the alternator was fed into the chamber.
The first run showed a draw of 5 amps into the chamber and about 6 pounds per square inch (psi), valve closed, in the chamber after 1 minute. Now the psi should be clarified here. The water in the chamber must be high enough to completly submerge the plates with enough extra to allow for the water to be consumed. A final version would have a float valve to allow fresh water to enter and maintain this level. My point here is that the "air" space above the water level, including the pipe leading to the valve, was about 1/2 liter. So the 6 psi was on a volume of 1/2 liter after 1 minute. I know I am mixing english and metric units here but I think you get the idea.
My friend Mike was excited but I pointed out that the piston motor consumes many liters per hour, although not all of it is fuel. So we added another 1/2 gram of electrolyte to the solution. This doubled the amp draw to 10 amps, and nearly doubled the output of HHO gas to 10 psi, again in 1 minute.
So we open the valve and fed the HHO gas, via a hose, into the throat of the carb. Yes the motor sound changed pitch, a slight increase in rpm's. No we did not have a tachometer on it, sorry.
A problem showed up. The water in the chamber was turning brown, well yellow at first then brown. The iron in the stainless steel plates was being driven, electrically, into the solution. The plates were being "eaten". This we called the brown sludge. Some of it was at the bottom of the chamber and some at the top, on the bubbles like foam on beer. That's why we tried other plate materials, each showed it's own drawback.
We melted connections getting the electricity into the chamber. We had three small explosions, well one was just a hose bursting, but very exciting nonetheless.
We played with this for a couple of months. We wanted more amperage than the alternator wanted to give us. We looked up alternator tricks. We unhooked the electrical output of the alternator and used a large battery charger instead. 90 amps, about 45 psi in 1 minute. We even hooked up a large 3 phase Lincoln welder I have capable of 400 amps. It showed 140 amps into the chamber at 28 volts. The water was bubbling so furiously and we were laughing equally hard. Then we realized that the water was boiling!!!
OK, bottom line. A 1 liter measured amount of gasoline was put in the tank, the engine ran with no load for 22 minutes, quitting on it's own. Another 1 liter of gasoline was added to the tank. HHO gas from the chamber was fed into the carb, using the battery charger at about 70 amps (don't remember the exact amps on this run) not the alternator, so engine not under load. The engine ran 44 minutes.
So there you have it. If you can supply the amps... If you can solve the brown sludge... If you can provide for cooling the solution... If you can contain the psi...