X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 14 Jun 2012 12:28:07 -0400 Message-ID: X-Original-Return-Path: Received: from nm11-vm1.bullet.mail.ne1.yahoo.com ([98.138.91.40] verified) by logan.com (CommuniGate Pro SMTP 5.4.5) with SMTP id 5599026 for lml@lancaironline.net; Thu, 14 Jun 2012 07:40:27 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.91.40; envelope-from=casey.gary@yahoo.com Received: from [98.138.90.53] by nm11.bullet.mail.ne1.yahoo.com with NNFMP; 14 Jun 2012 11:39:52 -0000 Received: from [98.138.87.5] by tm6.bullet.mail.ne1.yahoo.com with NNFMP; 14 Jun 2012 11:39:52 -0000 Received: from [127.0.0.1] by omp1005.mail.ne1.yahoo.com with NNFMP; 14 Jun 2012 11:39:52 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 32800.59069.bm@omp1005.mail.ne1.yahoo.com Received: (qmail 93691 invoked by uid 60001); 14 Jun 2012 11:39:52 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=6Qezvr/RrBd8M4Kl6Q73rhxAHUXWCdHi86cIK/ywS+9iEHC6dISjFA3Gl+RmqvfsMhJ37H9wSWuyibjP9efDwFj9HwxnXO1y8sR2RDtKODnmkyvgSzWU9f9aertwa1LryKhdVRL6N6Ia4Ub8eahItB53aX2rmTpNz0hOrj67inQ=; X-YMail-OSG: QEVie_kVM1l1Gdt4nLmSdXnYuJ5LeS9DcH9oglnlTqG1MfZ uTRSl1z2ELGxUsQEtua6Nv9QZYlNSSKz6zYAhfwia9CwjK6lr4QSYJbxdSQU j9eMFAFlZ7NWn384pGNpOtF5RKwCCvnoEjLhi_XSqghM0FM7pyPyAIWEsWvV 9XeYboq3uKYXFPxxf2QF3VyeU8Pz9D2zzvHP5v1ZrHiucIdpd97EsVNCU3w2 V0K5j6P4dNhJ2vswTWswWMmGDZ02VedNcGTJZ0NEj2xGpKSQZhAjqKr0RkQt nXcOKzqzUHFnnEjAQCDPwhUrJEIPLOkWkKij65WhKaSwOIfkS14Oc7ASsbvl TIb2ddEwa5DE6ueDssmshgUxn.MAvCxt05nkQipBjvWgGjCnQK2QTTYztqGf IdY_G0ILIXe4d5dldR9Ih8.I6TvFjsC_YzRaQ6QtqzN6XBtoVEVXjqNBG1PS 1 Received: from [71.208.251.202] by web125605.mail.ne1.yahoo.com via HTTP; Thu, 14 Jun 2012 04:39:51 PDT X-Mailer: YahooMailWebService/0.8.118.349524 References: X-Original-Message-ID: <1339673991.84572.YahooMailNeo@web125605.mail.ne1.yahoo.com> X-Original-Date: Thu, 14 Jun 2012 04:39:51 -0700 (PDT) From: Gary Casey Reply-To: Gary Casey Subject: Re: Airflow Performance questions X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-1124617404-1637096713-1339673991=:84572" ---1124617404-1637096713-1339673991=:84572 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable To add to Scott's reply, yes, the system is essentially a copy of the "Bend= ix" system now built by Precision Airmotive. =A0At one time it ws the only = non-certified system available, but now Precision also makes a system for e= xperimental aircraft. =A0To the best of my knowledge the experimental syste= m is the same as the certified one - it just doesn't come with a pedigree. = =A0The very same engine-driven diaphragm pump can be used, and an electric = backup pump is (almost?) always fitted. =A0Since the supplied pressure does= not effect fuel flow the electric pump is just that - a backup.=0AGary Cas= ey=0A=0ADoes the Airflow Performance fuel injection use an engine-powered p= ump, or does it rely on the electrical pump for fuel delivery all the time?= =A0 Is there a difference in the principle of operation of this system comp= ared to the standard Lycoming fuel injection system or the Silver Hawk syst= em?=0A=A0=0A=A0=0AGary Fitzgerald=0A=0AGary,=0A=A0=0AThe Bendix injection s= ystem for smaller Lycomings requires that the throttle body have a minimum = fuel pressure to operate through the spider properly.=A0 It doesn't care ho= w the minimum pressure is maintained.=A0 Typically, the engine driven provi= des pressure in excess of the minimum and that help reduce inline vaporizat= ion.=A0 Typically, an electric pump is also designed to deliver this excess= pressure fuel.=A0 In these systems, pressure regulation occurs at the pump= .=A0 In Other systems, pressure may be regulated by regulation at the throt= tle body by sending excess fuel back to the tank from whence it came.=A0 If= you are interested, you should study complete aviation=A0fuel systems that= you may be able to find on the internet.=0A=A0=0ATo answer your question, = most fuel system do no rely on non-engine driven pump to maintain the press= ure although certain specialized my require such high constant pressure tha= t a separate pump designed to maintain that pressure is used.=0A=A0=0AScott= Krueger ---1124617404-1637096713-1339673991=:84572 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
To add to Scot= t's reply, yes, the system is essentially a copy of the "Bendix" system now= built by Precision Airmotive.  At one time it ws the only non-certifi= ed system available, but now Precision also makes a system for experimental= aircraft.  To the best of my knowledge the experimental system is the= same as the certified one - it just doesn't come with a pedigree.  Th= e very same engine-driven diaphragm pump can be used, and an electric backu= p pump is (almost?) always fitted.  Since the supplied pressure does n= ot effect fuel flow the electric pump is just that - a backup.
Ga= ry Casey

Does the Airflow Performa= nce fuel injection use an engine-powered pump, or does it rely on the elect= rical pump for fuel delivery all the time?  Is there a difference in t= he principle of operation of this system compared to the standard Lycoming = fuel injection system or the Silver Hawk system?
 
 
Gary Fitzgerald

Gary,
 
The Bendix injection system for smaller Lycomings re= quires that the throttle body have a minimum fuel pressure to operate throu= gh the spider properly.  It doesn't care how the minimum pressure is maintained.  Typically, the engine driven provides pressure in excess= of the minimum and that help reduce inline vaporization.  Typically, = an electric pump is also designed to deliver this excess pressure fuel.&nbs= p; In these systems, pressure regulation occurs at the pump.  In Other= systems, pressure may be regulated by regulation at the throttle body by s= ending excess fuel back to the tank from whence it came.  If you are i= nterested, you should study complete aviation fuel systems that you ma= y be able to find on the internet.
 
To answer you= r question, most fuel system do no rely on non-engine driven pump to mainta= in the pressure although certain specialized my require such high constant = pressure that a separate pump designed to maintain that pressure is used.
 
Scott Krueger
---1124617404-1637096713-1339673991=:84572--