I've tried for months to explain this to anakpawis... and I'll try one more time
Imagine two hills of equal height with a valley in between. Let's say there is a rock on top of the left hill and you start it rolling down toward the valley. You need to push it to overcome inertia, then gravity does the rest. The rock will roll downhill transferring some of its energy as friction and heat on the dirt, some of it as friction to the air, and some as sound. When it reaches the bottom, it has given up a total of X amount of energy, part of which was transferred to the dirt and air, the rest of which is contained in the kinetic motion of the rock.
Now, it stands to reason that in order for the rock to reach the peak of the next hill, it will require X amount of energy. The problem is, you've lost a bunch coming down the hill, you'll lose more going up the hill, and it will never make it. What happens is the rock comes to rest at the bottom of the valley having expended all of its energy.
Gasoliine is like the rock at the top of the hill. It exists at a high level of potential energy. We use a spark as the "push" to get it started. Combustion is the rock rolling down the hill. Energy loss in an engine is like the friction of the rock on the dirt and air. A typical automotive engine is only about 27% efficient, meaning of the available energy locked in the gasoline's bonds, only 27% of it makes it to the crankshaft. Then of THAT energy, only about 75% makes it to the ground.
Water is like the rock at the bottom of the hill. It has ZERO energy potential. In order to use it, we have to put X energy INTO it to separate it (push the rock up the hill) just so we can combust it and roll the rock down the hill again. Each time (in a car engine) we go through this cycle we lose most of the energy.
What you are proposing is for the rock to not only perpetually go up and down the hill on its own with no outside energy input, you are asking it to supply SURPLUS energy for us to use. What you are proposing is not even perpetual motion, its perpetual motion WITH ENERGY TO SPARE. Not gonna happen.
Keep in mind that NONE of this takes into consideration the thermodynamic properties of the Hydrogen/Oxygen combustion process. The reaction is so fast and so violent that any attempt to burn it in a metal automotive engine would be instantly catastrophic. It has been tried with hydrogen fuel cells. Nothing has even come close to tolerating the extreme pressures that are seen inside the engine. You've seen engines with Nitrous Oxide I'm sure. Nitrous works by injecting N2O and additional fuel. Since ambient air is 21% oxygen and Nitrous is 33% oxygen, it provides significant gains in potential output. A simple small injection of Nitrous raises the typical intake charge to about 27% oxygen with intense results. Modifications to engine internals including pistons, rings, compression, ignition timing, and cooling systems are often required. Even then, you have the huge hydrocarbon molecule chains in gasoline that burn very slowly and at about 2200 degrees farenheit. Burning hydrogen in the presence of pure stoichiometric oxygen ratios can make flame fronts in excess of 7400 degrees at STP. Put that reaction in a 4-stroke engine and you're looking at 9-10 times that number. One revolution of the engine and you can kiss every metal part goodbye. Gasoline contains large atoms joined into large molecules. Hydrogen is the simplest of all elements and exists as a diatomic particle that is infinitesmally smaller than gasoline droplets. Its combustion is NOT something that can happen inside a cast iron or cast aluminum engine. Some manufacturers have been experimenting with ceramics that can handle the heat, but nothing has been able to contain the explosion so far. You're talking about replacing the ambient inlet air of 21% oxygen with 100% oxygen. Uh... no.
Water IS NOT a fuel in any way shape or form. If you want a HYDROGEN powered car, go for it. Use solar electricity or wind power to supply a tank of H2 and O2, then pump it into your car, but it will still require more wind or solar energy to electrolyze the gases than you will get back as power to the ground. You cannot get back more than you put in. Even if you attached a windmill to your car, it will take more energy to push the windmill than you get back from its operation. Even if you designed an engine with zero friction, made no noise and no heat, you would still lose energy to the tires, the driveline, the air, and a half million other things like turn signals, bearings, and natural resistance in wiring.
If you had any idea how far off you were, you would have ceased your arguments three months ago. Instead of listening to engineers, technicians, scientists, and experts, you have blindly told us we're idiots and instead have now started preaching the Gospel according to YouTube.
I triple dog-dare you to post your thoughts over at www.eng-tips.com.
It is a forum of the worlds finest engineers. If you're so certain of your designs, ask about them over there and see what the reaction is.