Return-Path: Received: from [199.185.220.224] (HELO priv-edtnes40.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 359012 for flyrotary@lancaironline.net; Tue, 10 Aug 2004 03:40:14 -0400 Received-SPF: none receiver=logan.com; client-ip=199.185.220.224; envelope-from=haywire@telus.net Received: from Endurance ([142.179.62.182]) by priv-edtnes40.telusplanet.net (InterMail vM.6.01.03.02 201-2131-111-104-20040324) with SMTP id <20040810073942.HWTX9484.priv-edtnes40.telusplanet.net@Endurance> for ; Tue, 10 Aug 2004 01:39:42 -0600 From: "Todd Bartrim" To: "Rotary motors in aircraft \(E-mail\)" Subject: returnless fuel system Date: Tue, 10 Aug 2004 00:39:40 -0700 Message-ID: <018001c47ead$32b06700$0101a8c0@Endurance> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0181_01C47E72.86518F00" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2910.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2742.200 Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_0181_01C47E72.86518F00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit First I'd like to thank everybody for their congrats on & offline, everybody is still doing fine, but sleep is still at a premium. Definitely no time for flying :-(, maybe in a few days. No jump seat in the 9 yet, but I'm already planning it :-) Second I need to say that even though I seem to have found a successful fuel system, I do regret not adding fuel return fittings in each of my 6 tanks. A simple 1/4" bulkhead fitting with a cap is not too much $$$, or weight and it will allow simple plumbing changes if ever necessary. While I have 30 successful flight hours on my returnless system, it is prudent to remember that I only have 30 flight hours on my returnless system.:-). And none of this flight time was down south where your idea of summer & winter are vastly different than up here in the great white north. At this point I'd recommend that you install return fittings while it's still easy to do. I wish I had, however if I had I may not have ever tried this system and only went with a conventional system. Even if my system continuous to be successful, if I ever have a reason to remove my tanks, I will add return fittings with caps. I may have this opportunity. I currently have capacitive fuel sensors, which are read by an E.I.sensor. I bought the components to build a converter as per Jim Weirs plans from a past KitPlanes article, in order to display on the EM2 which needs a 0-5 volt signal. However I find that auto fuel seems to vary in it's capacitance. When properly calibrated they are very accurate, but put in fuel from another batch and the readings are less accurate, put in fuel from the original batch and they are accurate again. Start adding pre-mix fuel and of coarse they're inaccurate again. I'm unsure if it is the fuel itself that has dielectric variations or possibly the dye used to mark the fuel as off-road use only? I've noticed that the purple colour seems to vary as some batches seem to have almost no colour while others are very dark. In any event, while I will still leave the capacitive probes in place, I think I will order a set of float resistive sensors to display fuel info on the EM2. If I do this I will add the return fittings and then possibly I may add an electric fuel tank selector valve that I have, except that it will be used to select fuel destination instead of source. In it's normal un-energized state it will continue to operate as a returnless system, but when energized it will return to a wing tank. In the event of an unexpected vapour lock, I can just hit a mom-on push button to return to a wing tank. My concern with this is that these fuel tank selector valves are meant to be located on the suction side of the fuel pump, so I'm unsure how well they would work in the return line. Bottom line... Install the return fittings while still it's easy! Todd Bartrim (trying to think of a way to burn diapers for fuel) RV9Endurance 13B Turbo Rotary C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm "The world will always have a place for those that bring hard work and determination to the things they do." ------=_NextPart_000_0181_01C47E72.86518F00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

    First I'd like to = thank=20 everybody for their congrats on & offline, everybody is still doing = fine,=20 but sleep is still at a premium. Definitely no time for flying :-(, = maybe in a=20 few days.  No jump seat in the 9 = yet, but=20 I'm already planning it :-)

    Second I need to = say that=20 even though I seem to have found a successful fuel system, I do regret not = adding fuel=20 return fittings in each of my 6 tanks. A simple 1/4" bulkhead fitting = with a cap=20 is not too much $$$, or weight and it will allow simple plumbing changes = if ever=20 necessary. While I have 30 successful flight hours on my returnless = system,=20 it is prudent to remember that I only have 30 flight hours on my = returnless=20 system.:-). And none of this flight time was down south where your idea = of=20 summer & winter are vastly different than up here in the great white = north.=20 At this point I'd recommend that you install return fittings while it's = still=20 easy to do. I wish I had, however if I had I may not have ever tried = this system=20 and only went with a conventional system. Even if my system continuous = to be=20 successful, if I ever have a reason to remove my tanks, I will add = return=20 fittings with caps.

    I may = have this=20 opportunity. I currently have capacitive fuel sensors, which are read by = an=20 E.I.sensor. I bought the components to build a converter as per Jim = Weirs plans=20 from a past KitPlanes article, in order to display on the EM2 which = needs a 0-5=20 volt signal. However I find that auto fuel seems to vary in it's = capacitance.=20 When properly calibrated they are very accurate, but put in fuel from = another=20 batch and the readings are less accurate, put in fuel from the original = batch=20 and they are accurate again. Start adding pre-mix fuel and of coarse = they're=20 inaccurate again. I'm unsure if it is the fuel itself that has = dielectric=20 variations or possibly the dye used to mark the fuel as off-road use = only? I've=20 noticed that the purple colour seems to vary as some batches seem to = have almost=20 no colour while others are very dark.

    In any event, while I will = still leave=20 the capacitive probes in place, I think I will order a set of float = resistive=20 sensors to display fuel info on the EM2. If I do this I will add the = return=20 fittings and then possibly I may add an electric fuel tank selector = valve that I=20 have, except that it will be used to select fuel destination instead of = source.=20 In it's normal un-energized state it will continue to operate as a = returnless=20 system, but when energized it will return to a wing tank. In the event = of an=20 unexpected vapour lock, I can just hit a mom-on push button to return to = a wing=20 tank. My concern with this is that these fuel tank selector valves are = meant to=20 be located on the suction side of the fuel pump, so I'm unsure how well = they=20 would work in the return line.

Bottom = line... Install=20 the return fittings while still it's easy!

Todd Bartrim        = (trying to=20 think of a way to burn diapers for fuel)
 
RV9Endurance
13B Turbo Rotary
C-FSTB
http://www3.telus.= net/haywire/RV-9/C-FSTB.htm
 
          &nbs= p; =20 "The world will always have a place for those that bring hard work and=20 determination to the things they do."
 
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