How about an HH bubbler on bike instead
Run Your gas MB with supplemented Hydrogen from Aluminum and Lye. (no electrolysis)
hydrogen generator H2O + Al -> AlO2 + H2 + heat
How it works.
Put Aluminum into a tank of Lye (sodium hydroxide and water). Caution Lye is just as dangerous as acid.
The Sodium Hydroxide peels off the Aluminum Oxide surface from the Aluminum allowing water to come into contact with Aluminum metal. The Aluminum immediately oxidizes, ripping the water's Oxygen atoms away to make Aluminum Oxide.(collect and recycle please) That releases the Hydrogen which bubbles out to be burned in the engine.
This reaction produces pure Hydrogen as apposed to electrolysis which produces brown gas (O & H = explosion) I would place the reaction chamber behind you! Run the Hydrogen tube through a series of vinegar (mild acid) bottle bubblers to help neutralize any caustic vapor from the reaction chamber this also prevents back flash. From there I would run the Hydrogen tube through a dryer (like the ones on compressors) and then the final destination is the intake. You now have a Gas/Hydrogen hybrid MB.
The reaction: H2O + Al -> AlO2 + H2 + heat
The reaction chamber must be able to handle heat and the caustic lye. You need to be able to add (fuel) water, lye and Aluminum as needed. Just think of it as a kind of low psi Hydrogen boost bottle.
