X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from nm19.bullet.mail.ac4.yahoo.com ([98.139.52.216] verified) by logan.com (CommuniGate Pro SMTP 5.4c2o) with SMTP id 4881871 for flyrotary@lancaironline.net; Thu, 24 Feb 2011 21:15:38 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.52.216; envelope-from=ceengland@bellsouth.net Received: from [98.139.52.192] by nm19.bullet.mail.ac4.yahoo.com with NNFMP; 25 Feb 2011 02:15:02 -0000 Received: from [98.139.52.143] by tm5.bullet.mail.ac4.yahoo.com with NNFMP; 25 Feb 2011 02:15:02 -0000 Received: from [127.0.0.1] by omp1026.mail.ac4.yahoo.com with NNFMP; 25 Feb 2011 02:15:02 -0000 X-Yahoo-Newman-Id: 51585.51479.bm@omp1026.mail.ac4.yahoo.com Received: (qmail 65770 invoked from network); 25 Feb 2011 02:15:01 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bellsouth.net; s=s1024; t=1298600101; bh=E58HONtRIlCLOdlT7/FymepsMuFKZ+3gm8fyIyEIyto=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:References:In-Reply-To:Content-Type; b=b+KTrusmbLjCztO/WX3eukaLLoHzwk8wFjRLFTYPCRhseFTFTTe1v/rZZK9ZfS3fLFtRQ3TL/r7YaeYcWw9Q5q3c78tKfltUsEqUibCkwYLYmwVNh/WTNgjF/KtjOkOx3TrRDo6aYRVCneFttiu8DX2xA+1lzsr7spdCgmRXGvk= Received: from [192.168.10.5] (ceengland@74.240.6.77 with plain) by smtp104.sbc.mail.re3.yahoo.com with SMTP; 24 Feb 2011 18:15:01 -0800 PST X-Yahoo-SMTP: uXJ_6LOswBCr8InijhYErvjWlJuRkoKPGNeiuu7PA.5wcGoy X-YMail-OSG: sGoJMHkVM1lBChB5yWhHlJYErtWrOc84dMyaRdA818YBK0u bxsUz2ZGnEqbkb.lI7JUQ8aK0zFPVWBAK3DZGpzDuCMH8nWC_ObhljUKugbc Ovo4r5LPAWzqCw1KuoZ8F89FlFTOroR7ALW98zZFani_UUiEBs0BsE.qKWBk 5uEgdN_ZNWRQv2O2JPbS113zEsYqoSDZfQL3tufo44q.fZKqdyWDylZxLpJY GbI0rbFrUjE.JPRypa290trtNV2Z2t9EMlpOBpZFtzPgExEE9LoqZ9GsaeJy 8QOgm3C8jydgCaC6VE.sKbio4I27oCk4eKwkONqRLKD6EKkSvBCLmk3bjGq_ YHfU7jJT8ZbiEY6Gsb6yMqRQ6C9_1Ia5jPLMD6oNX1cYw4tomtp.U X-Yahoo-Newman-Property: ymail-3 Message-ID: <4D6710D3.80802@bellsouth.net> Date: Thu, 24 Feb 2011 20:15:47 -0600 From: Charlie England User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.13) Gecko/20101207 Thunderbird/3.1.7 MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Fwd: Fuel injector pump cooling?? References: In-Reply-To: Content-Type: multipart/alternative; boundary="------------020409050206050106070004" This is a multi-part message in MIME format. --------------020409050206050106070004 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Yep, pumping fuel overboard is the reason I'm barely considering the idea. Compromised main tank supply is kind of a show stopper in all the scenarios, though. Overcoming return line pressure is one of the motivations for using another fuel injection pump for fuel transfer. It's nice to know it's not new territory. Charlie On 2/24/2011 6:13 PM, Steven W. Boese wrote: > > Charlie, > > I transferred fuel to a T in the return line from the regulator. The > regulator return was connected to the side branch of the T. I suspect > that the back pressure from this connection adversely affected the > flow rate from the Facet pump. A separate line to the main tank or a > different connection arrangement at the T might have been better. The > high pressure pump had a higher and predictable flow rate. > > While returning the fuel to only the main tank would work, it seems to > leave the possibility for a couple of undesirable situations. > > One would be in the event that the supply from the main tank were > compromised, fuel would have to be drawn from the aux tank while the > returned fuel would accumulate in the main tank where it would be > inaccessible and possibly vented. > > A second possibility would be to draw fuel from the aux tank and > return it to an operational but full main tank where it would be > vented. I'm sure you would not do this. Me?... I'm not so sure. > > Steve > > *From:*Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] > *On Behalf Of *Charlie England > *Sent:* Thursday, February 24, 2011 4:18 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Fwd: Fuel injector pump cooling?? > > Ouch; I hadn't thought about that. But I suspect that even a low > pressure pump would damage the tank if the vent is blocked. Thanks for > the data point on the fact that a high pressure pump can be used > effectively as a transfer pump. > > Were you using a separate port on the main tank for your transfer > point? My tentative plan is to T into either the regulator return, or > (assuming an effective back/anti-siphon setup), into the main supply > between tank & engine pump. Obviously, the anti-siphon feature would > need to be bullet proof to tap the supply line. > > One option I've considered is to use the fuel selector 'normally', but > have all regulator bypass return to a single 'main' tank. This > arrangement is actually used in some certified planes with injected > Continentals, but I'm leery of having my primary engine pump run dry > for even a very short interval as I empty an aux tank. I suppose that > with that arrangement, it would only run dry for a couple of seconds ( > :-> ), so maybe it would work out fine. Any thoughts? > > > > Charlie > --------------020409050206050106070004 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Yep, pumping fuel overboard is the reason I'm barely considering the idea. Compromised main tank supply is kind of a show stopper in all the scenarios, though. Overcoming return line pressure is one of the motivations for using another fuel injection pump for fuel transfer. It's nice to know it's not new territory.

Charlie


On 2/24/2011 6:13 PM, Steven W. Boese wrote:

Charlie,

 

I transferred fuel to a T in the return line from the regulator.  The regulator return was connected to the side branch of the T.  I suspect that the back pressure from this connection adversely affected the flow rate from the Facet pump.  A separate line to the main tank or a different connection arrangement at the T might have been better.  The high pressure pump had a higher and predictable flow rate.

 

While returning the fuel to only the main tank would work, it seems to leave the possibility for a couple of undesirable situations.

 

One would be in the event that the supply from the main tank were compromised, fuel would have to be drawn from the aux tank while the returned fuel would accumulate in the main tank where it would be inaccessible and possibly vented.

 

A second possibility would be to draw fuel from the aux tank and return it to an operational but full main tank where it would be vented.  I’m sure you would not do this.  Me?... I’m not so sure.

 

Steve

 

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Charlie England
Sent: Thursday, February 24, 2011 4:18 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Fwd: Fuel injector pump cooling??

 

Ouch; I hadn't thought about that. But I suspect that even a low pressure pump would damage the tank if the vent is blocked. Thanks for the data point on the fact that a high pressure pump can be used effectively as a transfer pump.

Were you using a separate port on the main tank for your transfer point? My tentative plan is to T into either the regulator return, or (assuming an effective back/anti-siphon setup), into the main supply between tank & engine pump. Obviously, the anti-siphon feature would need to be bullet proof to tap the supply line.

One option I've considered is to use the fuel selector 'normally', but have all regulator bypass return to a single 'main' tank. This arrangement is actually used in some certified planes with injected Continentals, but I'm leery of having my primary engine pump run dry for even a very short interval as I empty an aux tank. I suppose that with that arrangement, it would only run dry for a couple of seconds ( :-> ), so maybe it would work out fine. Any thoughts?



Charlie

 


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