Return-Path: Received: from fed1rmmtao05.cox.net ([68.230.241.34] verified) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 359765 for flyrotary@lancaironline.net; Tue, 10 Aug 2004 12:50:53 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.34; envelope-from=ALVentures@cox.net Received: from BigAl ([68.107.116.221]) by fed1rmmtao05.cox.net (InterMail vM.6.01.03.02.01 201-2131-111-104-103-20040709) with ESMTP id <20040810165016.UTFJ14278.fed1rmmtao05.cox.net@BigAl> for ; Tue, 10 Aug 2004 12:50:16 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: returnless fuel system Date: Tue, 10 Aug 2004 09:50:19 -0700 Message-ID: <002601c47efa$1ebc09a0$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0027_01C47EBF.725D31A0" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Importance: Normal In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_0027_01C47EBF.725D31A0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Subject: [FlyRotary] Re: returnless fuel system =20 during his flight with Dave Leonard, he personally observed 45 gallons = per hour fuel return with one of Tracy's pumps on and 80 gallons per hour = with both pumps on!! Dave has a flow meter on his return line. =20 =20 That may be what the meter is reading, but (I believe) not = representative. I don't have the data handy, but I once pulled up some specs on the pump = (or equivalent) that I got from Tracy, and I think about 30 gph was max, and maybe less at 40psi. One reason for exceptional high readings from a Floscan type meter downstream from a pressure regulator is there are = almost always bubbles in the fuel as some low vapor pressure fractionates flash = due to the sudden pressure drop, especially if there has been some heating = as the fuel traversed the fuel rails. =20 Al =20 Wow, is that true Dave? That seems high, but I have no way of measuring = it. I run both pumps all the time (aside from testing them individually = during preflight), so I guess my fuel stays pretty well stirred :-) =20 Rusty (yes I know you don't need to run both all the time)=20 ------=_NextPart_000_0027_01C47EBF.725D31A0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

Subject: [FlyRotary] Re: returnless fuel system

 

during his flight with Dave Leonard, he personally observed 45 gallons per hour fuel return = with one of Tracy's pumps on and 80 gallons = per hour with both pumps on!!  Dave has a flow meter on his return line.   

 

That may be = what the meter is reading, but (I believe) not representative.  I = don’t have the data handy, but I once pulled up some specs on the pump (or = equivalent) that I got from Tracy, and I think about 30 gph was max, and maybe less = at 40psi.  One reason for exceptional high readings from a Floscan = type meter downstream from a pressure regulator is there are almost always bubbles = in the fuel as some low vapor pressure fractionates flash due to the sudden = pressure drop, especially if there has been some heating as the fuel traversed = the fuel rails.

 <= /font>

Al

 

Wow, is that = true Dave?  That seems high, but I have no way of measuring = it.  I run both pumps all the time (aside from testing them = individually during preflight), so I guess my fuel stays pretty well stirred = :-)

 

Rusty (yes I = know you don't need to run both all the time) 

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