Walter, et al,
This is a response to your noodling about some device to properly feed the
injectors with air pressure to assist in atomization.
You noted that up to 3" Hg (1.5 psi, 41" H2O) would assist atomization
- perhaps even optimize it. Of course, when the MAP is 3" less than, uh,
possible, we would have most beneficial atomization. On the
ground when taxiing, I use 10"-12" MAP whilst the surrounding air
pressure is 29"+, there is too much pressure. Lowering the speed (IAS) to
enter the traffic pattern or whilst on approach, I need a MAP of 13" to
17", still too much pressure difference. However, hi speed cruising
at 3000-4000 feet whilst retarding the throttle to 25" MAP results
in conditions that are almost ideal when utilizing ram air to the
injectors.
So, the question is, "How to boost that air pressure at higher
altitudes?"
Do we need a pressure regulator if over boosting the pressure causes no
improvement or harm?
What about using the filtered output from an existing vacuum pump
(with a relief valve, of course)?
If you have an all electric airplane, then just using a
spare vacuum pump to assist the injection air might be, uh,
interesting.
If there is an Electronic Ignition, how about using the magneto drive
to operate a pump.
How about a small dc electric pump (aquarium?)?
What about warming the air to cause expansion?
After all, I know there are engineers that could carry these simple
calculations further:
Suppose the bleed holes are .025 in diameter. Suppose there are 6 of
them. What CFM requirement is there for an air pump to maintain 1.5+
PSI thru ports with an area totaling .003 square inches? Maybe a
diaphragm aquarium pump would work.... Hmmmmmm........
Scott AKA Grayhawk