One of the Anton group said something about modifing the engine into a way that the explosion and implosion mustnt work against eachother....
So i went reading.
This i found:
"Does Brown's Gas implode ?"
Among the "wonderful" properties of "Brown's Gas" is that when ignited it doesn't explode, it implodes. That is, the reaction product has a smaller volume than the initial gas mixture. Is this true? Is it remarkable? The answers to these two questions are "Not exactly" and "No." Brown's Gas is that you get if you electrolyze water and keep the resulting hydrogen and oxygen mixed together. Let me make two important comments at this point. One is that it would be extremely hazardous to store any large quantity of Brown's Gas, either at atmospheric pressure or in compressed form. A spark, or the presence of any material which catalyzes the hydrogen/oxygen reaction, will cause a devastating explosion. The second comment is that all the energy which comes from burning Brown's Gas was put into it by the electrical energy used to electrolyze the water. In a loose sense, since Brown's Gas could be used as fuel for an engine and, since Brown's Gas is made from water, one could say that one was running a car on water. However, the power driving the car is coming entirely from the electrical input, not from the water. A car "driven" by Brown's Gas would either have to carry a large tank of compressed gas (see my point one) or drag a long power cord behind it. If you had electrical power available you would be much, much better off driving the car with an electric motor than fooling around with a gas generator and a gas powered motor.
So does Brown's Gas explode? Yes, of course it does. As it happens, in my foolhardy youth I once filled a polyethylene bag with a mixture of hydrogen and oxygen and lit it from a safe distance. It exploded very satisfactorily and made a very loud boom. Many of NASA's rockets, including the Space Shuttle, burn hydrogen and oxygen. If Brown's Gas always imploded, the rockets would be sucked into the ground.
What you may have seen, and I have seen, is some Brown's Gas being put into a cylinder and then being ignited. The piston in the cylinder is sucked in with a thump. However, if the piston was free to move outwards it would fly across the room. Brown's Gas would be great in spud guns. When ignited, Brown's Gas explodes, that is it burns rapidly, generating hot, high pressure gas, in this case, water vapor. Because it is inside a long, narrow, room temperature cylinder the water vapor rapidly condenses into liquid water, heating the cylinder as it does so. Since the water has much less volume than the hot vapor the pressure inside the cylinder drops suddenly, pulling in the piston. The cylinder heats up in the process, the heat energy from the burning Brown's Gas has to go somewhere. If the experiment were to be repeated, for example in a continuously operating engine, the cylinder would get hotter and hotter and eventually the internal pressure would blow it apart. So the answers are: Does Brown's Gas implode? No, Brown's Gas explodes like any other combustible gas mixture. Is this remarkable? No, except that in this case the combustion product, water, readily condenses to a liquid.
