It makes sense to have the "bleed" line be located as close to the injectors, but difference in the time that it would take to clear the air out of the system would be minimal after the pump is air free. ( the "T" for the return line should point UP).
Georges B.
-------Original Message-------
Date: 06/15/05 07:13:58
Subject: [FlyRotary] EFI Bleeder Circuit (Was Engine Not Starting)
Jofar,
The real purpose of the bleed circuit is to allow the pump to reprime
itself. Once that happens, the pump builds up pressure again, and
forces all the remaining air out through the pressure regulator. With a
5-gal tank sitting on the floor, my system (running one pump) can
reprime itself in about 10 seconds. Yes, under the right circumstances,
that could be the longest 10 seconds of my life. This should only
happen if you run a tank dry. But if that happens, the procedure will
be to switch to the other tank (should have fuel), then turn on the
boost pump. That should reduce the recovery time to something less than
10 seconds.
Mark
-----Original Message-----
Behalf Of jesse farr
Sent: Wednesday, June 15, 2005 8:47 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Engine Not Starting
I don't know nothing (actually pretty much anything) about any of this
but
that has never stopped me from having and voicing an opinion; so, if
injectors only fire small percentage of time and fuel & compressed air
flow
not sufficient at times to clear out in time to get started while flying
ac,
bleed return definitly sounds like good idea. But, if sufficiently far
away
from injectors, then even though now have flow established to the bleed
point, you will still have slow go to purge remaining compressed air,
vapor
and allow fuel to actually flow from there to injectors and inject. It
may
just take a few seconds longer but that is still a tight a-- time of
flying,
starting, praying, cursing own stupidity, etc.. Could I suggest might be
better to put bleed point at end of fuel rail so as to pass vapor all
the
way more quickly ? After all, small orfice and line return to tank
shouldn't
create that much more of a problem. Is there some other problem there
that I
simply do not know enough to understand ?
jofarr, soddy tn
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