X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3730183 for flyrotary@lancaironline.net; Tue, 23 Jun 2009 21:35:47 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (sv1-1.per.aanet.com.au [203.24.100.68]) by poplet2.per.eftel.com (Postfix) with ESMTP id 8F0661738AA for ; Wed, 24 Jun 2009 05:51:30 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 7790EBEC028 for ; Wed, 24 Jun 2009 05:51:28 +0800 (WST) Message-ID: <153AB309C3744E65BAB17E237F771B62@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Duty Cycle for Injectors Date: Wed, 24 Jun 2009 07:51:31 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0015_01C9F4A0.96A72190" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 090623-0, 06/23/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0015_01C9F4A0.96A72190 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Gary, It is interesting that the Bendix system was/is a reasonably high = pressure system. I have been reading about the progressive development of injection = system and find it very interesting. Quite obviously you have the knowledge and now that I have your ear, I = am eager to learn more about your low pressure systems. Personally I would like to have a low pressure mechanical system. I was = reading about one such system that had a 'spoon like' fuel actuation = injection device . I may be reading more into it than there is, however = it sounds, to me, like a small airfoil within the inlet manifold, = whereby the air speed and density had a direct effect upon the actuation = of the metered fuel - purely mechanical. To me that sounds ideal for = light aircraft application. My preference in no way 'poo-poos' = computerized fuel management systems or direct injection, rather I see = it as the poor mans simplified system. I still see the need for an O2 = sensor for monitoring a manual leaning facility. George (down under) George, Well, there are "low pressure systems" and "low pressure systems". = Depends on the point of view, I guess. We're not talking about high = pressure direct injection (GDI) systems that are now all the rage. The = original Bendix system ran at 39 psi - a little higher than the Bosch = systems at the time,which were, I think 29 psi (exactly 2 bar - a = coincidence?) systems. The reason was that one of our applications was = the Cadillac V8 and the injectors were in a hotter location. The higher = pressure was to keep vapor formation at bay during a hot soak. Then = some turbo Chrysler applications used 60 psi for the same reason. The = injector design was the same and most injectors will still open at = pressures up to about 100 psi. There were some lower pressure systems = (about 20 psi, I think) that used clever injector designs to reduce = sensitivity to vapor formation. Well, I thought they were clever = because some were mine. Higher pressure operation can improve = atomization, but that isn't a big consideration. Lower pressure systems = once allowed a lower cost fuel pump to be used, but that isn't true any = more. No, I don't think lower pressure systems are coming back. None of this discussion pertains to the "Bendix" aircraft injection = system, which is a totally different concept. Gary -------------------------------------------------------------------------= ----- -----Inline Message Follows----- Cary, Very interesting, thank you for that info. Bendix is a low pressure injector system is it not? I have been reading about the benefits of low pressure systems - are = they coming back in vogue? George ( down under) ------=_NextPart_000_0015_01C9F4A0.96A72190 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Gary,
It is interesting that the Bendix = system was/is a=20 reasonably high pressure system.
I have been reading about the = progressive=20 development of injection system and find it very = interesting.
 
Quite obviously you have the knowledge = and now that=20 I have your ear, I am eager to learn more about your low pressure=20 systems.
 
Personally I would like to have a low = pressure=20 mechanical system.  I was reading about one such system that had a = 'spoon=20 like' fuel actuation injection device . I may be reading more into = it than=20 there is, however it sounds, to me, like a small airfoil within the = inlet=20 manifold, whereby the air speed and density had a direct effect upon the = actuation of the metered fuel - purely mechanical. To me that sounds = ideal for=20 light aircraft application. My preference in no way 'poo-poos' = computerized=20 fuel management systems or direct injection, rather I see it as the poor = mans=20 simplified system. I still see the need for an O2 sensor for = monitoring a=20 manual leaning facility.
George (down under)
George,
Well, there are "low pressure systems" and "low pressure = systems". =20 Depends on the point of view, I guess.  We're not talking about = high=20 pressure direct injection (GDI) systems that are now all the = rage. =20 The original Bendix system ran at 39 psi - a little higher than the = Bosch=20 systems at the time,which were, I think 29 psi (exactly 2 bar - a=20 coincidence?) systems.  The reason was that one of our = applications was=20 the Cadillac V8 and the injectors were in a hotter location.  The = higher=20 pressure was to keep vapor formation at bay during a hot soak.  = Then some=20 turbo Chrysler applications used 60 psi for the same reason.  The = injector design was the same and most injectors will still open at = pressures=20 up to about 100 psi.  There were some lower pressure systems = (about 20=20 psi, I think) that used clever injector designs to reduce sensitivity = to vapor=20 formation.  Well, I thought they were clever because some were=20 mine.  Higher pressure operation can improve atomization, but = that isn't=20 a big consideration.  Lower pressure systems once allowed a lower = cost=20 fuel pump to be used, but that isn't true any more.  No, I don't = think=20 lower pressure systems are coming back.
 
None of this discussion pertains to the "Bendix" aircraft = injection=20 system, which is a totally different concept.
Gary



-----Inline Message Follows-----

Cary,
Very interesting, thank you for that=20 info.
Bendix is a low pressure injector = system is it=20 not?
I have been reading about the = benefits of low=20 pressure systems - are they coming back in vogue?
George ( down under)
 
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