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Date: Wed, 14 Mar 2007 19:50:35 -0600
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Speaking of Mistral....?
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Hi Chris,

For the bypass regulators as sold by Summit racing, etc. a pinhole
restriction in front of the regulator doesn't sound right.  They work by
bypassing enough fuel to maintain the proper pressure at the exit end
of the fuel rail. If you have a regulator in front of the fuel rail,
I'm guessing it would be a series regulator where the regulator allows
enough gas to flow to give the proper pressure.  The pinhole would
allow a vapor lock to be cleared easier.  Some people have used a
pinhole restriction to connect the input and output of the bypass
regulators for that reason. I've only used the bypass regulator and am
only guessing that there may be a series type.  The regulator on a gas
(as in helium, oxygen, etc.) bottle is the series type.

Did Mistral provide the pump and/or regulator?

Bob W.

On Wed, 14 Mar 2007 19:15:06 -0600
"Christopher Barber" <CBarber@TexasAttorney.net> wrote:

> 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.
> 
> All the best,
> 
> Chris Barber
> Houston, Texas
> 
> www.LoneStarVelocity.com
> 


-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight:  11/23/2006 7:50AM - 3.8 Hours Total Time
Cables for your rotary installation - http://www.roblinphoto.com/shop/