Bill Freeman wrote:

Paul,

I really like the undercowl venturi with a butterfly valve to
feed it.  Pick up the air in the stagnated area of the front of
the cowl and you will have zero additional drag with the
valve shut, and absolutely reliable vacuum with it open.
You'll want a piece of tubing from the outlet of the venturi to
the cowling outlet, but this should be very reliable, simple
light,  all the things that a critical backup system should be.

I also like the PM alternator built into the flywheel.  You will
need the flywheel to provide for the starter ring gear, so add the
magnets (new ultra magnets can make this even better) and
the coils.  No wearing parts, solid state regulator - perhaps it would
be best to have this system *normally* powering the FI and ignition,
with the battery/alt system for cockpit loads and backup.
The primary advantage here is that the more likely to fail system
(battery/alt) does not affect the FI/ignition.  Back to a self-
contained system, which is the primary advantage of mags.

Good thinking, guys!  Discussion does often work out good ideas.

Bill

I like the undercowl venturi so much I am thinking of forgetting the vacuum pump. 
Turn it off when flying VFR. Less HP loss and less weight. I don't believe
in an HSI or a directional gyros anyway with today's solid state/vertical card
compasses and GPS heading. 

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org