Return-Path: Received: from [24.25.9.102] (HELO ms-smtp-03-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 2908135 for flyrotary@lancaironline.net; Sun, 28 Dec 2003 09:34:06 -0500 Received: from o7y6b5 (clt78-020.carolina.rr.com [24.93.78.20]) by ms-smtp-03-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id hBSEY1ow001234 for ; Sun, 28 Dec 2003 09:34:03 -0500 (EST) Message-ID: <000a01c3cd4f$423b5140$1702a8c0@WorkGroup> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Fuel Coolers Date: Sun, 28 Dec 2003 09:31:18 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C3CD25.58B5CF60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0007_01C3CD25.58B5CF60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message -----=20 From: Haywire=20 To: Rotary motors in aircraft=20 Sent: Sunday, December 28, 2003 1:45 AM Subject: [FlyRotary] Fuel Coolers Hi Guy's; I'm looking for a small, compact fuel cooler of some sort. I tried = Google, but get a ton of listings for ******partstore.com, but none of = them actually lead to any fuel coolers. I did find one other but it was = for a fairly large cooler (12"x3"). I was hoping for something closer to = 3"x4". I've been monitoring the firewall temp at the location of my fuel = pumps and filters (on the cool side of the engine) and it is = consistently around 60C, while doing touch & goes. I'm considering = putting a tee in my return line to install a temp sensor to measure fuel = temp before it returns to the header tank as I suspect that it is = considerably warmer than this, due to heat from the turbo charger, which = is in fairly close proximity to the injection rail.=20 During extended touch and goes, the turbocharger is producing full = power every few minutes and I've began to use both boost pumps while in = the circuit. this combination seems to contribute to a build up of = vapour in the header tank. I also keep the boost pump on to keep the = header tank pressurized to 7psi to help counter the vapour issue.=20 A few days ago, after an hour of touch and goes, the vapour press = apparently built to 7psi and during my pre-landing checks while on = downwind for runway 33, I found that one of the FI pumps had just begun = to cavitate indicating vapour-lock. I immediately switched on both boost = pumps, but the second boost pump began to cavitate also, followed = shortly after by that eerie silence that we all hate. I immediately = began to vent the pressure off the header tank while continuing to pump = to it, and set-up for a dead-stick landing onto 24. Landing was = uneventful and restart was easy as soon as the excess vapour pressure = was vented from the header tank. I understand the conditions that contributed to this, and it can = be overcome by venting build-up pressure on a timed basis, but I prefer = to keep the header tank as a closed system while in-flight. I realize = the Ed is the only one who is flying with a similar system using a = header tank. Ed, if IRCC you had similar problems with vapour lock = before you switched to Avgas?=20 Now many of you will suggest that I just switch to Avgas, but that = is not an affordable option for me. The price difference here is so = horrendous as to make the difference between whether I can afford to fly = or not. Of course I'm not willing to risk continued vapour problems to = save money either, but rather try to find an affordable solution that = will safely solve the problem. My current plan is to shroud the fuel pumps and filter to isolate = them from the cowl heat and duct a 2" hose from a NACA duct like the = ones used for ventilation on an RV (and probably many others) to this = shroud, but have the air pass through a small fuel cooler located at the = air inlet to the shroud. Exit air from the shroud would have its own = exit out the bottom of the cowl. So my question for the list is does anybody know of a source for = an off-the-shelf compact fuel cooler? Any other suggestions would also = be appreciated. While I've considered the option of doing away with the = header tank, at this point I'd like to try to keep it as it does have = advantages for managing 6 fuel tanks. Ps.... This really isn't as bad as it sounds... really :-) S. Todd Bartrim Turbo 13B RV-9Endurance C-FSTB http://www3.telus.net/haywire/RV-9/C-FSTB.htm Hi Todd, Glad to hear your incident did nothing more than re-arrange your = seat cushion. I have never had a situation of impending vapor lock = (such as caviation of the EFI pumps) that turning on the boost pump did = not resolve. I do however, have my fuel pumps and header tank shielded = with a fiberglass box covered with aluminum foil. I also have an NACA = duct funneling outside air to the box. So I think your plans would = certainly help the situation. Plus, you may have a bit more heat under = you cowl what with the turbocharger. Other than my header pipe which do = a 90 deg bend and out from the cowl - nothing much of a heat producer, = also I do have louvers on both sides as well as a rather large opening = on the bottom. I had considered a fuel line cooler (which they do make), but = unless you are funneling cool outside air to it (and no inside hot air) = then it could make the problem worst by picking up more heat from the = hotter under the cowl air. In any case, I have not tried a fuel line = cooler, but would think that provided with cooling air, its couldn't = hurt. But, Yes, I have found auto gas to be more conducive to percolation = than Av Gas.=20 Ed Anderson Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ------=_NextPart_000_0007_01C3CD25.58B5CF60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
Message -----
From:=20 Haywire
Sent: Sunday, December 28, 2003 = 1:45=20 AM
Subject: [FlyRotary] Fuel = Coolers

Hi=20 Guy's;
   =20 I'm looking for a small, compact fuel cooler of some sort. I tried = Google, but=20 get a ton of listings for ******partstore.com, but none of them = actually lead=20 to any fuel coolers. I did find one other but it was for a fairly = large cooler=20 (12"x3"). I was hoping for something closer to 3"x4". I've been = monitoring the=20 firewall temp at the location of my fuel pumps and filters (on the = cool side=20 of the engine) and it is consistently around 60C, while doing touch = &=20 goes. I'm considering putting a tee in my return line to install a = temp sensor=20 to measure fuel temp before it returns to the header tank as I suspect = that it=20 is considerably warmer than this, due to heat from the turbo charger, = which is=20 in fairly close proximity to the injection rail.
   =20 During extended touch and goes, the turbocharger is producing full = power every=20 few minutes and I've began to use both boost pumps while in the = circuit. this=20 combination seems to contribute to a build up of vapour in the header=20 tank. I also keep the boost pump on to keep the header tank = pressurized=20 to 7psi to help counter the vapour issue.
   =20 A few days ago, after an hour of touch and goes, the vapour press = apparently=20 built to 7psi and during my pre-landing checks while on downwind for = runway=20 33, I found that one of the FI pumps had just begun to cavitate = indicating=20 vapour-lock. I immediately switched on both boost pumps, but the = second boost=20 pump began to cavitate also, followed shortly after by that eerie = silence that=20 we all hate. I immediately began to vent the pressure off the header = tank=20 while continuing to pump to it, and set-up for a dead-stick landing = onto 24.=20 Landing was uneventful and restart was easy as soon as the excess = vapour=20 pressure was vented from the header tank.
   =20 I understand the conditions that contributed to this, and it can be = overcome=20 by venting build-up pressure on a timed basis, but I prefer to keep = the header=20 tank as a closed system while in-flight. I realize the Ed is the only = one who=20 is flying with a similar system using a header tank. Ed, if IRCC you = had=20 similar problems with vapour lock before you switched to Avgas?=20
   =20 Now many of you will suggest that I just switch to Avgas, but that is = not an=20 affordable option for me. The price difference here is so horrendous = as to=20 make the difference between whether I can afford to fly or not. Of = course I'm=20 not willing to risk continued vapour problems to save money either, = but rather=20 try to find an affordable solution that will safely solve the=20 problem.
   =20 My current plan is to shroud the fuel pumps and filter to isolate them = from=20 the cowl heat and duct a 2" hose from a NACA duct like the ones used = for=20 ventilation on an RV (and probably many others) to this shroud, but = have the=20 air pass through a small fuel cooler located at the air inlet to the = shroud.=20 Exit air from the shroud would have its own exit out the bottom of the = cowl.
   =20 So my question for the list is does anybody know of a source for an=20 off-the-shelf compact fuel cooler? Any other suggestions would also be = appreciated. While I've considered the option of doing away with the = header=20 tank, at this point I'd like to try to keep it as it does have = advantages for=20 managing 6 fuel tanks.
 
        = Ps....=20 This really isn't as bad as it sounds... really = :-)

S. Todd Bartrim
Turbo 13B = RV-9Endurance
C-FSTB
http://www3.telus.net/haywire/RV-9/C-FSTB.htm

=  Hi=20 Todd,

    Glad to hear your = incident did=20 nothing more than re-arrange your seat cushion.  I have never had = a=20 situation of impending vapor lock (such as caviation of the EFI pumps) = that=20 turning on the boost pump did not resolve.  I do however, have my = fuel=20 pumps and header tank shielded with a fiberglass box covered with = aluminum=20 foil.  I also have an NACA duct funneling outside air to the = box. =20 So I think your plans would certainly help the situation.  Plus, = you may=20 have a bit more heat under you cowl what with the turbocharger.  = Other=20 than my header pipe which do a 90 deg bend and out from the cowl=20 - nothing much of a heat producer, also I do have louvers on both = sides=20 as well as a rather large opening on the bottom.

     I had = considered a fuel=20 line cooler (which they do make), but unless you are funneling cool = outside=20 air to it (and no inside hot air) then it could make the problem worst = by=20 picking up more heat from the hotter under the cowl air.  In any = case, I=20 have not tried a fuel line cooler, but would think that provided with = cooling=20 air, its couldn't hurt.

   But, Yes, I have = found auto=20 gas to be more conducive to percolation than Av Gas.

 Ed Anderson

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
 
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