Ok, so a little background. I'm looking at ways of evaporating (at least some of) the fuel prior to it hitting the engine, to increase fuel efficiency. In addition, given that water is an integral part of the combustion process (
http://open-source-energy.org/?topic=2431.msg33797#msg33797), I'm looking at ways of adding moisture to the intake air to facilitate efficient combustion. And a third goal is to get rid of the PCV valve and put a slight vacuum on the crankcase to reduce windage losses, increase the effective pressure across the piston during the power stroke, and sweep blowby gasses out of the crankcase before they can contaminate the oil.
So as an experiment, I'll be doing something like what you see in the attached image:
The crankcase gasses are routed to an oil catch can, then to the top of the gas tank through a check valve.
The gas tank "burp line" at the top of the filler neck is tapped into (the original function, to burp air from the top of the tank during filling, is left intact) and routed to the water tank through a check valve.
The water tank "burp line" at the top of the filler neck is tapped into and routed through an En-Valve (which maintains a consistent 6 inches Hg of vacuum), which is then routed to the intake manifold.
The crankcase blow-by gasses and any oil vapor are dissolved into the gasoline in the fuel tank. Any gas that evaporates is routed through the water tank. Thus the gasses being pulled through the En-Valve and into the intake are fuel and water laden.
There's little risk of explosion, the crankcase gasses are low-oxygen exhaust gasses that slipped by the rings. There won't be a lot of flow... just the amount of blow-by past the rings, which is a product of engine speed... the higher the engine speed, the more blow-by gasses, thus the more flow through this system.
I'm considering putting a small venturi in the intake, so even at WOT, there will be a bit of suction on this system. Thus, at low throttle, the intake vacuum will maintain vacuum on this system. At high throttle, the venturi vacuum will maintain vacuum on this system.
The ECU will sense the extra fuel being added via this system and cut back the fuel injector PWM duty cycle to compensate. Eventually, I'll have a new programmable ECU that'll let the engine run lean, but for now, it's just an experiment with fuel evaporation and water vapor intake.
The entire premise behind this is that a good portion of the fuel injected into our engines is used not for propulsion, but to cool the combustion process prior to it hitting the exhaust valve. As combustion progresses, the fire goes out because the fuel:air ratio becomes too
rich... not because all the fuel is burnt up, but because all the oxygen is consumed. The fuel droplets injected via the fuel injector have only a few milliseconds to absorb enough heat to vaporize, and some of them don't... by design. They continue to evaporate after combustion has ceased, thereby cooling things down so the exhaust valve doesn't get burnt. That's why we have such things as the PAIR system on our scooters... it injects extra air into the exhaust to burn off that fuel that didn't burn in-cylinder because the droplets didn't vaporize in time.
That's why, as you lean out the engine, it actually runs hotter... there's less fuel after combustion ends to vaporize and absorb the heat of combustion. I propose to replace the cooling effect of that extra fuel with water, which is needed by the combustion process anyway, and is an end result of the combustion process in any case. The water vapor in the diagram above won't do much to help cool the cylinder, it's there strictly to facilitate more efficient combustion. Eventually, after I get the new programmable ECU installed, there will be an ECU-controlled water injector on the bike.
And before you go all wild-eyed and start issuing warnings about water in the engine, you should know that I've dumped 90 ml of water straight into the gas tank the last couple tankfuls... an amount that is small enough that at prevailing temperatures, the ethanol in the fuel can absorb it. My fuel efficiency is at an all-time high, and the engine is running stronger than ever.
So... what do you think?
