Return-Path: Received: from mtiwmhc12.worldnet.att.net ([204.127.131.116] verified) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 529131 for flyrotary@lancaironline.net; Fri, 12 Nov 2004 10:28:51 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.131.116; envelope-from=keltro@att.net Received: from 204.127.135.43 ([204.127.135.43]) by worldnet.att.net (mtiwmhc12) with SMTP id <2004111215282111200lti84e>; Fri, 12 Nov 2004 15:28:21 +0000 Received: from [209.247.222.95] by 204.127.135.43; Fri, 12 Nov 2004 15:28:21 +0000 From: keltro@att.net (Kelly Troyer) To: "Rotary motors in aircraft" Subject: [FlyRotary] Re: EFI stuff Date: Fri, 12 Nov 2004 15:28:21 +0000 Message-Id: <111220041528.27469.4194D6940008EBB000006B4D2158766755019D9B040A05@att.net> X-Mailer: AT&T Message Center Version 1 (Oct 18 2004) X-Authenticated-Sender: a2VsdHJvQGF0dC5uZXQ= MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="NextPart_Webmail_9m3u9jl4l_27469_1100273301_0" --NextPart_Webmail_9m3u9jl4l_27469_1100273301_0 Content-Type: text/plain Content-Transfer-Encoding: 8bit Barny and All If you will note the schematics of most of the fuel systems posted the fuel valve is placed before the pumps (inlet side). Since EFI pumps are better at pushing than pulling fuel I wanted my pumps as close to the fuel tanks as possible (I wanted to avoid a booster pump to a header tank also) . For my Delta that required the fuel valve to be located to the rear of the A/C and would require a remote selector unless I ran a lot of extra fuel lines to plumb the valve forward within reach . That was my reason for needing the secondary bypass valves that Marv found . My fuel valve can now be located forward within reach on the high pressure side of the EFI pumps . I had not even thought of the other problems mentioned by Marv caused by pressure on the valve or the effect of pressure spikes on the engine . Not cheap but the best way for my installation . FWIW -- Kelly Troyer Dyke Delta/13B/RD1C/EC2 -------------- Original message from "Marvin Kaye" : -------------- > The "check" valves you mentioned aren't actually check valves. Check valves > have a very low cracking pressure (0.5-2psi) and are intended to basically > free flow in one direction and block flow in the other. These valves are > called secondary bypass valves and they open at 50psi, just a bit higher than > our regulated pressure. They serve several purposes... first, without them > when it's time to switch tanks and you turn on the pump you'll be switching > to, that pump's full pressure is dead-heading against the body of the selector > valve, not good for the pump, and if you don't switch immediately you'll blow > the breaker (don't ask me how I know). Second, hi-pres pumps don't typically > have an internal bypass, so the pump's full pressure pushing on the body of > the selector valve makes it very difficult to switch tanks for anyone with > less-than Popeye arms. Third, the pressure buildup against the valve without > them causes a sudden spike in fuel pressure when the selector is actually > switched and can cause a very-rich-followed-by-lean condition as the FP > regulator deals with the spike and then its absence. The whole idea is to > keep the fuel pressure on both sides of the selector valve within reasonable > limits to facilitate the several things I've mentioned above (and probably > more). > > All I can tell you is that I wish I'd put them in in the first place. > > > > "Barnhart" : > > Marv, > > What is the function of the check valve between the feed and the return > line? > > I have my return line running straight back to the tanks from the regulator > on the fuel rail. > > Barny > MGDQ 20bt > ----- Original Message ----- > From: Kelly Troyer > To: Rotary motors in aircraft > Sent: Thursday, November 11, 2004 7:21 PM > Subject: [FlyRotary] Re: EFI stuff > > > Marv, > Thanks a million .......My fuel system is now finalized.......The rest > of > the > group could do themselves a favor and copy as much of your fuel system > as will work for their respective projects!! Very professional and well > thought > out . The JPG's print out very well. > > Thanks again, > -- > Kelly Troyer > Dyke Delta/13B/RD1C/EC2 > > > > > > > -------------- Original message from "Marvin Kaye" > : -------------- > > > > HI Kelly, > > > > No, I just accepted their 50psi number... our fuel pressure seems to > run > > around 40-43psi (as set by the engine manufacturer) so even if they're > off by > > -10% we'll be ok. > > > > I've saved the picture as several JPGs... it still might be hard to > read, > > though, as the only print on it is very tiny. I hope you can piece it > > together so it makes some sense. > > > > keltro@att.net (Kelly Troyer): > > > > Marv, > > Did you opt to pay the extra $20.00 per valve to have them flow > > and pressure tested for the exact cracking pressure ? Also can you > > resubmit your fuel system schematic in other than DXF which I cannot > open ? > > > > Thanks, > > -- > > Kell! y Troyer > > Dyke Delta/13B/RD1C/EC2 > > > > -------------- Original message from "Marvin Kaye" : > > -------------- > > > > > No problem, Kelly... sharing and solutions is what we're all here > for. > BTW, > > > the valves that I ordered are their part number 3156. It's a hard > anodized > > > aluminum housing with -6 AN flares, looks just like a check valve. > Difference > > > is that check valves typically have cracking pressures from .5 to 2 > psi... > > > this one opens at 50psi (to work with an EFI system that operates at > 45.) You > > > can find it three items down the middle column at the top of page 35M > in > > >their > > > online catalog (better to download their complete PDF catalog, only > about 7mb > > > and pretty quick on broadband). They've got _WAY_ too many cool > things > for > > > EFI to not include them in one's list of resources. --NextPart_Webmail_9m3u9jl4l_27469_1100273301_0 Content-Type: text/html Content-Transfer-Encoding: 8bit
Barny and All
  If you will note the schematics of most of the fuel systems posted the
fuel valve is placed before the pumps (inlet side). Since EFI pumps are
better at pushing than pulling fuel I wanted my pumps as close to the
fuel tanks as possible (I wanted to avoid a booster pump to a header
tank also) . For my Delta that required the fuel valve to be located to the
rear of the A/C and would require a remote selector unless I ran a lot of
extra fuel lines to plumb the valve forward within reach .
 
  That was my reason for needing the secondary bypass valves that Marv
found . My fuel valve can now be located forward within reach on the high
pressure side of the EFI pumps . I had not even thought of the other
problems mentioned by Marv caused by pressure on the valve or the effect
of pressure spikes on the engine . Not cheap but the best way for my installation .
 
FWIW
--
Kelly Troyer
Dyke Delta/13B/RD1C/EC2




-------------- Original message from "Marvin Kaye" <marv@lancaironline.net>: --------------


> The "check" valves you mentioned aren't actually check valves. Check valves
> have a very low cracking pressure (0.5-2psi) and are intended to basically
> free flow in one direction and block flow in the other. These valves are
> called secondary bypass valves and they open at 50psi, just a bit higher than
> our regulated pressure. They serve several purposes... first, without them
> when it's time to switch tanks and you turn on the pump you'll be switching
> to, that pump's full pressure is dead-heading against the body of the selector
> valve, not good for the pump, and if you don't switch immediately you'll blow
> the breaker (don't ask me how I know). Second, hi-pres pumps don't typically
> have an internal bypass, so the pump's full pressure pushing on the body of
> the selector valve makes it very difficult to switch tanks for anyone with
> less-than Popeye arms. Third, the pressure buildup against the valve without
> them causes a sudden spike in fuel pressure when the selector is actually
> switched and can cause a very-rich-followed-by-lean condition as the FP
> regulator deals with the spike and then its absence. The whole idea is to
> keep the fuel pressure on both sides of the selector valve within reasonable
> limits to facilitate the several things I've mentioned above (and probably
> more).
>
> All I can tell you is that I wish I'd put them in in the first place.
>
>
>
> "Barnhart" :
>
> Marv,
>
> What is the function of the check valve between the feed and the return
> line?
>
> I have my return line running straight back to the tanks from the regulator
> on the fuel rail.
>
> Barny
> MGDQ 20bt
> ----- Original Message -----
> From: Kelly Troyer
> To: Rotary motors in aircraft
> Sent: Thursday, November 11, 2004 7:21 PM
> Subject: [FlyRotary] Re: EFI stuff
>
>
> Marv,
> Thanks a million .......My fuel system is now finalized.......The rest
> of
> the
> group could do themselves a favor and copy as much of your fuel system
> as will work for their respective projects!! Very professional and well
> thought
> out . The JPG's print out very well.
>
> Thanks again,
> --
> Kelly Troyer
> Dyke Delta/13B/RD1C/EC2
>
>
>
>
>
>
> -------------- Original message from "Marvin Kaye"
> : --------------
>
>
> > HI Kelly,
> >
> > No, I just accepted their 50psi number... our fuel pressure seems to
> run
> > around 40-43psi (as set by the engine manufacturer) so even if they're
> off by
> > -10% we'll be ok.
> >
> > I've saved the picture as several JPGs... it still might be hard to
> read,
> > though, as the only print on it is very tiny. I hope you can piece it
> > together so it makes some sense.
> >
> > keltro@att.net (Kelly Troyer):
> >
> > Marv,
> > Did you opt to pay the extra $20.00 per valve to have them flow
> > and pressure tested for the exact cracking pressure ? Also can you
> > resubmit your fuel system schematic in other than DXF which I cannot
> open ?
> >
> > Thanks,
> > --
> > Kell! y Troyer
> > Dyke Delta/13B/RD1C/EC2
> >
> > -------------- Original message from "Marvin Kaye" :
> > --------------
> >
> > > No problem, Kelly... sharing and solutions is what we're all here
> for.
> BTW,
> > > the valves that I ordered are their part number 3156. It's a hard
> anodized
> > > aluminum housing with -6 AN flares, looks just like a check valve.
> Difference
> > > is that check valves typically have cracking pressures from .5 to 2
> psi...
> > > this one opens at 50psi (to work with an EFI system that operates at
> 45.) You
> > > can find it three items down the middle column at the top of page 35M
> in
> > >their
> > > online catalog (better to download their complete PDF catalog, only
> about 7mb
> > > and pretty quick on broadband). They've got _WAY_ too many cool
> things
> for
> > > EFI to not include them in one's list of resources.
--NextPart_Webmail_9m3u9jl4l_27469_1100273301_0--