For gasoline to be burned in a Pontiac engine, three things need to occur. It must be atomized (broken into small particles), emulsified (mixed with air), and vaporized (changed into a rarefied form).

FIGURE 1—Here's the relationship between air flow through a venturi and how atmospheric pressure "pushes" fuel into the air stream. At the vena contracta, actual pressure is at a minimum (maximum flow ...