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I've often wondered if the "myth" of the 100 MPG carb, and using water as fuel, don't actually have their basis in fact, as do many other myths...

Way back when, when I had a 71 Pontiac Formula 400, I came upon a set of RAM AIR IV heads from an earlier model. In 1971, due to the fear of government regulations, GM dropped the compression ratios in their engines substantially. Bolting on those heads raised it way back up. As I recall, I was having a serious problem with detonation, as getting decent LEADED fuel back then was tough. I was using an after market octane booster, but it was pretty expensive, and inconvenient to use.

I called one of the premier Pontiac shops at the time (Nunzio's in Brooklyn, NY, I think... It's been 20 years!), and he mentioned something that was getting a bit of popularity... Water injection. The idea was that you could thin out the mixture somewhat, and really increase the ignition advance. The water injection would cool the mixture, making it more dense, allowing you to run it leaner. It would also resist detonation due to the cooling effect. It's been far too long to say exactly what settings I used, but I seem to recall that with the factory standard ignition advance, I was having serious detonation problems. But with the addition of water injection, I was able to increase the ignition timing by 6 or 8 degrees IIRC. It increased power (I didn't change my jetting, so I guess I wound up running a net richer mixture) and mileage by nearly 20 percent. Granted, in this case, that was about 4MPG. And the car was already pretty darned powerful. I never ran it on a dyno, but it did feel more powerful, strictly by seat of the pants measurements.

Maybe this is where the myth of high mileage carbs that use water comes from.

Mark

Water has been used to improve the performance of high compression engines at least since WWII. Water as a value of latent heat of evaporation which is quite high. This means that in order to cause it to vaporize it requires a lot of energy which in the engine takes heat out of the combustion or allows a slight increase in fuel use given the same temperatures and pressures. Since water slightly cools the intake charge before combustion it allows a slightly more dense charge of fuel with respect to air because the air volume is slightly displaced by the water and since the volumetric efficiency of the engine is finite over a certain range of operation the net air amount is decreased. This causes a slightly richer mixture because a carburetor doesn't know the difference between air or water vapor. A richer mixture often prevents knocking. When an engine doesn't knock it is using the available fuel most efficiently and this is where I suspect you gained fuel efficiency. To maximize the benifits of water injection one should consider turbocharging where water injection is syncronized with increase in manifold pressure and fuel delivery. This is where high performance gains can be realized, like in WWII air craft, but not for the purposes of increasing fuel mileage. Racing cars that use methanol use it because they can increase compression up to 15:1 and cool the charge as well but unlike water, alcohol is a fuel and provides the heat needed for power generation and alcohol evaporates readily at lower temperatures than both water and gasoline.

The whispering wheel is interesting because when I was a child I was interested in hybrid cars described much like the bus is now. This was over 30 years ago. The problem then is as now but not as severe. How does one control power to the motors without wasteing energy (heat)? Before power FET's it was difficult but even today it is not without energy loss. The article describes the bus not having bearings on the axles. It has to in order to roll even if the bearings are in the hub it will have a bearing surface somewhere. PM's have been the dream of high mileage cars for years but are limited in being able to allow high power density in an electric motor. It would be interesting to see one of these busses, loaded with passengers make it up one of the hills in the cities in Northeastern USA.