X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.2 cv=FaV1/926 c=1 sm=1 tr=0 a=yT2Xjf0HcXYXiMYguiPwaQ==:117 a=x7bEGLp0ZPQA:10 a=K7ySfSCCDxUA:10 a=Op4juWPpsa0A:10 a=pjdaNNIBAAAA:8 a=pGLkceISAAAA:8 a=Ia-xEzejAAAA:8 a=o1OHuDzbAAAA:8 a=_6GpL_ENAAAA:8 a=7g1VtSJxAAAA:8 a=NGyXV-UXtc3192p2sVgA:9 a=QEXdDO2ut3YA:10 a=bS0AdBRTcP7XbDhtPJoA:9 a=9gF5f2zkRipVwms6:21 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=Urk15JJjZg1Xo0ryW_k8:22 a=5YQ6H4ZxyGn-KoBYtt8s:22 a=grOzbf7U_OpcSX4AJOnl:22 From: "Matt Boiteau mattboiteau@gmail.com" Received: from mail-yw0-f174.google.com ([209.85.161.174] verified) by logan.com (CommuniGate Pro SMTP 6.2.1) with ESMTPS id 10672025 for flyrotary@lancaironline.net; Fri, 09 Feb 2018 01:02:36 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.161.174; envelope-from=mattboiteau@gmail.com Received: by mail-yw0-f174.google.com with SMTP id m84so4383767ywd.5 for ; Thu, 08 Feb 2018 22:02:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=LMN0PxqkhO9aOh/vyGDmgkdEHQrSZaqkblpi/dxqgQE=; b=qwE4aL/rWCgPrxQOW5qVB5XVdKHoYzxgVw5Vs0lSwze+xWObvwNYap00eJCm5CeWgh F9XPcKXRhcB7HN4qM4IYEtu6HYCTFe1zV9qSy1c5U13eUTgf43siPVA03UtMd5L63ECr Lc1Wes4PjFuiGp6igfEeW91e22x8wTpTZBPygSokQOxmmE90BnEW5LNUeQ73uZY3qxsS rNIHnCSkXaU3oN3IEHxUBj0turHi5mSz7R1J7mMNxI8hIu3VnfCtBvJsjFlf5eydudUm /Mn4XViH57dcanpexmBglkxUBcOtDWE4ZziteT1+d04vFGbuDEZcMFUMEjXewTpHzyF5 OflQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=LMN0PxqkhO9aOh/vyGDmgkdEHQrSZaqkblpi/dxqgQE=; b=mgF4AMp51fvnw1EVM/1NRNi2Xp29yh+SuNoaI3A60gLrnGCZDAamsKpRuNalAkTM+k acXP4WVW5oz3SAYKxlcFdptzIWLnN0OtSmBtC0fGNOg/df4Ys9XszJLN7q4ihd4sB6CO P0ReHN6op+aVGmPyzmpfxuyPOB2HCwdlEdLch7X7qtX7j5dT3ahQWixISUPyUle08/gm 5C7/yEdABU8xFS2k1RLd+/lZbHNSinyalEm/x5Mess/8GoCjeUZUs5KKsGANpj0WI34F Oh1l3IB+Y74Q8DNNvm+fWAhP0IqycYAlNbkW/2bHlZhhfYno9Ehty1VTp0QoLEkq5MOp +5OA== X-Gm-Message-State: APf1xPBBI8dzu3/wg5C7bNgCO0dYLgQdt8+jp66DbJRWWFqP/LSurZ1G /EnykXQhlG87RbskMeh8DBLHhK+4l3UlG4yWw77HRwJg X-Google-Smtp-Source: AH8x2275RnN1rRnSZcBkm9n+z+NbaADZCOD206+quFJ+Hid5aC++1qVqWDO23PHg0Otdp7Eqok6l7ga0wBvwacjIhWo= X-Received: by 10.37.128.13 with SMTP id m13mr1038012ybk.520.1518156140056; Thu, 08 Feb 2018 22:02:20 -0800 (PST) MIME-Version: 1.0 Received: by 10.37.203.86 with HTTP; Thu, 8 Feb 2018 22:02:19 -0800 (PST) In-Reply-To: References: Date: Fri, 9 Feb 2018 01:02:19 -0500 Message-ID: Subject: Re: [FlyRotary] Re: Fuel line sizes To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary="089e0828bf887116930564c145fc" --089e0828bf887116930564c145fc Content-Type: text/plain; charset="UTF-8" As Charlie said, the supply should always be equal or bigger then return.. Keep it simple, just stick with AN-6 for fuel. Here's the walbro 10mm to an-6 adapter https://www.ebay.com/p/Walbro-Inline-Fuel-Pump-Fitting-M10-X-1-to-6-an-Male-128-3039/1022214227 - Matt Boiteau On Thu, Feb 8, 2018 at 6:03 PM, Charlie England ceengland7@gmail.com < flyrotary@lancaironline.net> wrote: > On 2/8/2018 2:50 PM, Finn Lassen finn.lassen@verizon.net wrote: > >> Working on wing tanks for my RV-4. >> >> Pickup lines are spec'd at -6 (3/8") in Van's plans. >> >> Looking at a Walbro pump I replaced in my (Rusty's) RV-3B the inlet >> appear to be -6 but outlet is -4 (1/4") (fitting thread size -- so may >> actually be less). >> >> Rusty carried -6 all the way to fuel injection rail and back to fuel >> regulator, but -4 back to tank from fuel regulator. >> >> Also appears he used -4 from left wing to right wing fuel transfer. I'm >> using a 40105 Facet pump as transfer pump which appears to have 1/8"-27 INT >> fittings. It does seem to pump less than 30 GPH, but is pumping into same >> line as pressure regulator return line to tank. In the RV-4 I intend to >> have separate fittings in the right tank for fuel return and for transfer >> from left tank. >> >> So the question is: is there any valid reason to have more than -4 lines >> after transfer pump and after high pressure pumps and filters going to the >> engine (and back). Higher power draw by pumps because of pumping into -4 >> lines instead of -6? >> >> Obviously it'd be easier, less weight and less $ to use - 4 lines. >> >> Finn >> >> P.S. I think Tracy is running from the left tank, but I think advantage >> of running from the right tank is keep lines on the "cool" side of the >> engine. Probably minor. >> > Hi Finn, > > Here are a few data points from 'the other world'. One of the most > reputable Lycoming engine rebuilders says that he uses -4 (1/4") lines > *after* the engine driven fuel pump on their fuel injected engines (~25-30 > PSI), to minimize the volume of fuel that's near the hot engine. These are > 'returnless' injection systems; the fuel deadends at the injectors. Now, > everything up to the mechanical pump is -6, to minimize pressure drop (and > risk of vapor formation) with the pump 'sucking' on the line. > > IIRC, the plumbing around the engine on rotary cars is what amounts to > 5/16" lines; perhaps someone else can verify. > > My original plumbing on the -7 (not yet flying) had -6 up to the firewall, > and -4 to the engine. I followed Tracy's lead on the -8 by putting the > mechanical regulator right after the Walbro pumps, inside the fuselage, > with a -6 bypass line returning to the main tank. The pressure reference to > the regulator still gets plumbed to the intake manifold, of course. Logic > for the -6 return line is that the Walbro pumps 4 to 5 times the quantity > of fuel used by the engine, so I didn't want back pressure in the return > line to affect pressure delivered to the engine. I ended up T-ing the > transfer line from the other tank(s) into the regulator bypass line, so I'm > now really glad I used -6 for the bypass/return. Logic for keeping the > regulator aft of the firewall is that pumped, unused fuel never sees the > heat of the engine. If you do the math, the FWF fuel is always at ~40 psi, > so it'll be virtually impossible for it to flash into vapor before it exit > an injector. On the other hand, with the regulator on the engine's fuel > rail, the regulator is acting like the expansion valve in an air > conditioner circuit, guaranteeing that the returning fuel will collect > engine heat. > > I did change the FWF line from -4 to -6, but only because I decided to put > the final filter (same filter Ed Anderson & others are using) ahead of the > firewall, and the only A/N adapters for it are -6. > > I picked the right tank as the 'main' because the -7 has side-by-side > seating, and I figured that when I'm solo or when Tupper's flying right > seat, moving fuel to the right tank will balance a bit better. After > running the lines, I almost wish I'd made the left tank the main, because > plumbing would have been a bit simpler with everything on the left side of > the plane. > > The Walbro pumps that RWS were selling had 10 mm threaded fittings on both > ends. You can probably get A/N adapters in sizes other than -6, but I > definitely wouldn't go smaller than -6 on the source side, to avoid 'vapor > lock' on the input side of the pump. As you probably know, smaller line > does offer more resistance to flow, and any bend in the line can add the > equivalent of several feet of line (in flow resistance) to the length. > > I'd be surprised if there's enough cost difference between -4 & -6 line & > fittings to make a perceptible difference in the finished price of the > plane. And you could probably get it all back by buying the fittings on > ebay instead of the usual suspects. Not sure about buying aluminum line > itself from unknown sources, but the fittings I've bought seem to be just > fine; I wouldn't be surprised if they come out of the same factory as the > high-dollar stuff with USA branding on it. > > As I said above, If I were going small, I'd go small on the delivery side > and stay big on the return and supply sides. > > FWIW, > > Charlie > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline. > net:81/lists/flyrotary/List.html > --089e0828bf887116930564c145fc Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
As Charlie said, the supply should always be equal or bigg= er then return.. Keep it simple, just stick with AN-6 for fuel.=C2=A0
Here's the walbro 10mm to an-6 adapter
https://www.ebay.com/p/Walbro-Inline-Fuel-Pump-Fitting-M10-X-1-to-6-a= n-Male-128-3039/1022214227

- Matt Boiteau

On Thu, Feb 8, 2018 at 6:03 PM, Charlie Engl= and ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:
On 2/8/2018 2:50 PM, Finn Lassen finn.lassen@verizon.net<= /a> wrote:
Working on wing tanks for my RV-4.

Pickup lines are spec'd at -6 (3/8") in Van's plans.

Looking at a Walbro pump I replaced in my (Rusty's) RV-3B the inlet app= ear to be -6 but outlet is -4 (1/4") (fitting thread size -- so may ac= tually be less).

Rusty carried -6 all the way to fuel injection rail and back to fuel regula= tor, but -4 back to tank from fuel regulator.

Also appears he used -4 from left wing to right wing fuel transfer. I'm= using a 40105 Facet pump as transfer pump which appears to have 1/8"-= 27 INT fittings. It does seem to pump less than 30 GPH, but is pumping into= same line as pressure regulator return line to tank. In the RV-4 I intend = to have separate fittings in the right tank for fuel return and for transfe= r from left tank.

So the question is: is there any valid reason to have more than -4 lines af= ter transfer pump and after high pressure pumps and filters going to the en= gine (and back). Higher power draw by pumps because of pumping into -4 line= s instead of -6?

Obviously it'd be easier, less weight and less $ to use - 4 lines.

Finn

P.S. I think Tracy is running from the left tank, but I think advantage of = running from the right tank is keep lines on the "cool" side of t= he engine. Probably minor.
 Hi Finn,

Here are a few data points from 'the other world'. One of the most = reputable Lycoming engine rebuilders says that he uses -4 (1/4") lines= *after* the engine driven fuel pump on their fuel injected engines (~25-30= PSI), to minimize the volume of fuel that's near the hot engine. These= are 'returnless' injection systems; the fuel deadends at the injec= tors. Now, everything up to the mechanical pump is -6, to minimize pressure= drop (and risk of vapor formation) with the pump 'sucking' on the = line.

IIRC, the plumbing around the engine on rotary cars is what amounts to 5/16= " lines; perhaps someone else can verify.

My original plumbing on the -7 (not yet flying) had -6 up to the firewall, = and -4 to the engine. I followed Tracy's lead on the -8 by putting the = mechanical regulator right after the Walbro pumps, inside the fuselage, wit= h a -6 bypass line returning to the main tank. The pressure reference to th= e regulator still gets plumbed to the intake manifold, of course. Logic for= the -6 return line is that the Walbro pumps 4 to 5 times the quantity of f= uel used by the engine, so I didn't want back pressure in the return li= ne to affect pressure delivered to the engine. I ended up T-ing the transfe= r line from the other tank(s) into the regulator bypass line, so I'm no= w really glad I used -6 for the bypass/return. Logic for keeping the regula= tor aft of the firewall is that pumped, unused fuel never sees the heat of = the engine. If you do the math, the FWF fuel is always at ~40 psi, so it= 9;ll be virtually impossible for it to flash into vapor before it exit an i= njector. On the other hand, with the regulator on the engine's fuel rai= l, the regulator is acting like the expansion valve in an air conditioner c= ircuit, guaranteeing that the returning fuel will collect engine heat.

I did change the FWF line from -4 to -6, but only because I decided to put = the final filter (same filter Ed Anderson & others are using) ahead of = the firewall, and the only A/N adapters for it are -6.

I picked the right tank as the 'main' because the -7 has side-by-si= de seating, and I figured that when I'm solo or when Tupper's flyin= g right seat, moving fuel to the right tank will balance a bit better. Afte= r running the lines, I almost wish I'd made the left tank the main, bec= ause plumbing would have been a bit simpler with everything on the left sid= e of the plane.

The Walbro pumps that RWS were selling had 10 mm threaded fittings on both = ends. You can probably get A/N adapters in sizes other than -6, but I defin= itely wouldn't go smaller than -6 on the source side, to avoid 'vap= or lock' on the input side of the pump. As you probably know, smaller l= ine does offer more resistance to flow, and any bend in the line can add th= e equivalent of several feet of line (in flow resistance) to the length.
I'd be surprised if there's enough cost difference between -4 &= -6 line & fittings to make a perceptible difference in the finished pr= ice of the plane. And you could probably get it all back by buying the fitt= ings on ebay instead of the usual suspects. Not sure about buying aluminum = line itself from unknown sources, but the fittings I've bought seem to = be just fine; I wouldn't be surprised if they come out of the same fact= ory as the high-dollar stuff with USA branding on it.

As I said above, If I were going small, I'd go small on the delivery si= de and stay big on the return and supply sides.

FWIW,

Charlie

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