Chris;
As mentioned, it is designed for the
regulator plumbed in series with the fuel rail, and the pinhole is for bleed-off
of air in the rail. Some sort of rail air bleed is needed for the case
where the EFI pump is not in a low point of the system such that any air on the
inlet side would migrate back to the tank so the pump would will always self
prime.
Al
-----Original Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Christopher Barber
Sent: Wednesday, March 14, 2007
5:15 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Speaking of
Mistral....?
I have the Mistral intake
and am setting up my fuel lines. The lines go into the fuel rail through
a big hole (3/8?), but exit through a very tine "pin hole" on the
other end. I am not versed in fuel injection as my history is with carbs
in my ol' 65 Mustang ragtop.
During the first
incarnation my build buddy David had a pressure regulator installed before the
fuel rail. Then, following some internet research on fuel injection by
me, I found several sources that stated the pressure regulator is usually
installed downstream of the rail. David figured this may make sense, but
felt it should be T'ed back to the sump tank (sump per Velocity plans).
I looked at my friends
RV-7 who is installing an Eggennfelder Subaru which also has pin hole
restrictor and tried to copy its pressure regulator set up, however, Dave
and my mechanical engineering hangar mate, Richard, do not think it is
proper. I too wondered what the pressure regulator was actually doing
since it is downstream of the pin hole which provides a lot of restriction and
it was T'ed in a manner that went around the regulator and since the fuel would
go by the path of least resistance would in all likelihood bypass the fuel
pressure regulator almost completely.
I had another engineering
friend look at the set up (who btw has worked with some of the Mistral folks as
he is heavily involved in the aviation community...the company he owns provides
aircraft A/C systems for companies like Cirrus, Moony, Eclipse, Columbia and in
the last couple of months he has been in discussions with Cessna, Piper and
Honda Jet.....pretty good credentials....and he is the builder of the RV-7 with
the Eggenfeilder) He believes that the Mistral Intake does not need the
pressure regulator since the pin hole is doing the job of keeping the rail
"charged".
We have emailed the
contacts at Mistral who have not as of yet responded....it has been a couple of
weeks. I understand they cannot provide major tech support, but I would
love some direction. We hope to be great ambassadors for their
product. I would assume some basic tech info is available.
However, since I have yet
to hear from Mistral, do any of y'all have any insight and/or solutions as to
what would be "best" <g>.
Thanks, I am quite close
to first start, but I obviously need to resolve this question.