Originally Posted by
redrat100
Yes.
Solving for engine airflow rate, where:
3456 = volumetric constant
CFM = cubic feet per minute
CID = cubic inch displacement
RPM = revs per minute
VE = volumetric efficiency, assumed to be 75% (not to be confused with thermal efficiency which is around 25% at best)
Using your figures (500 rpm seems a bit low for idle... my 2L engine idles at 950 rpm):
CFM = (CID x RPM x VE)/3456
CFM = (122.047 {2 liters} x 500 x .75)/3456
CFM = 13.243 = 375 LPM
Your 2L engine pumps 375 lpm of fuel air mixture throught the combustion chambers at 500 idle rpm. So, your idle HHO percentage, at 10lpm, is really 2.67%.
Now for highway speeds. Substituting 3000 rpm in the above equation gives 79.46 CFM = 2250 LPM. Your 10 lpm HHO ratio freeway speeds is closer to .44%.
It seems the consensus here that 1 lpm HHO for every liter of engine displacement is what is required for measurable mileage increases. So the ratio is even lower. The trick is building a cell small enough, with a high enough output, with low power consumption.
Or, you could stuff a H2 gas cylinder into your trunk as you suggest but I would not want to be anywhere near the car when it goes off.