X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ironmaiden.mail.utexas.edu ([128.83.32.53] verified) by logan.com (CommuniGate Pro SMTP 5.1c.4) with ESMTP id 1413754 for flyrotary@lancaironline.net; Thu, 21 Sep 2006 14:45:07 -0400 Received-SPF: none receiver=logan.com; client-ip=128.83.32.53; envelope-from=mark.steitle@austin.utexas.edu DomainKey-Signature: s=main; d=austin.utexas.edu; c=nofws; q=dns; b=2eDfnEvmHFTpHVkKDAmvIrFCYO8OAtPe+BiRaN4VIf7X3L4ckqFrPHXM8EJuZfV+fX41e9HiF8qpqeFXOzQEWdwjByNKwaK9w49z2tx9ddm8K2zZuZ6GjPkkcOD0dCvtSmxyXurMzDM8Y+Y7/KhF5OXrQSuz30xkxU7NAOtxMKU=; Received: from exb02.austin.utexas.edu (HELO MAIL01.austin.utexas.edu) ([129.116.87.143]) by ironmaiden.mail.utexas.edu with ESMTP; 21 Sep 2006 13:36:17 -0500 Received: from MAIL02.austin.utexas.edu ([129.116.87.144]) by MAIL01.austin.utexas.edu with Microsoft SMTPSVC(6.0.3790.1830); Thu, 21 Sep 2006 13:36:17 -0500 X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C6DDAC.D2FFEA90" Subject: RE: [FlyRotary] Fuel Pressure Regulator Vacuum or Boost?? Date: Thu, 21 Sep 2006 13:36:16 -0500 Message-ID: <5B59870CA143DD408BD6279374B74C8BC3EED1@MAIL02.austin.utexas.edu> In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Fuel Pressure Regulator Vacuum or Boost?? Thread-Index: Acbdp27g3FN2zjg+SDa4Bg4b4hzPYAABUi5w From: "Mark R Steitle" To: "Rotary motors in aircraft" Return-Path: mark.steitle@austin.utexas.edu X-OriginalArrivalTime: 21 Sep 2006 18:36:17.0132 (UTC) FILETIME=[D308CAC0:01C6DDAC] This is a multi-part message in MIME format. ------_=_NextPart_001_01C6DDAC.D2FFEA90 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Sounds like a Lynn Hanover question to me. =20 =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson Sent: Thursday, September 21, 2006 12:58 PM To: Rotary motors in aircraft Subject: [FlyRotary] Fuel Pressure Regulator Vacuum or Boost?? =20 For the entire life of my rotary powered RV-6A, I have flown with a "Boost Referenced" adjustable fuel pressure regulator from MSD. As you know, it is desirable to keep the pressure differential between the injector fuel rail pressure and the manifold pressure a constant for best fuel injection control. =20 =20 I flew for several years thinking that since my pressure regulator was manifold reference that it was indeed doing this. Then the light bulb came on - my fuel pressure holds rock-steady at 43 PSI - and does not vary between idle and WOT! This certainly implies that the fuel pressure IS NOT varying as a function of manifold pressure. =20 Then doing some recent research on fuel pressure regulators, I noticed that some say they are "Boost Referenced" and other's say "Vacuum/Boost Referenced". My conclusion (which may be incorrect) is that while my pressure regulator is "Boost Referenced" it is not "Vacuum Referenced". The difference (If I understand it correctly ) is that my regulator would increase fuel pressure IF it ever encounter manifold pressure greater than ambient - since I am not used forced induction that never happens - which in turn appears to be the reason I never see the fuel pressure changing in response to manifold "vacuum". =20 So my question to those who realllllllyyyyyy know - is it correct that for my NA 13B I need a fuel pressure regulator that responses to manifold "Vacuum" or is the difference in description between "vacuum referenced and boost referenced " just semantics in advertising? =20 Thanks =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW ------_=_NextPart_001_01C6DDAC.D2FFEA90 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Sounds like a Lynn Hanover question = to me. 

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Ed Anderson
Sent: Thursday, September = 21, 2006 12:58 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Fuel = Pressure Regulator Vacuum or Boost??

 

For the entire life of my rotary powered RV-6A, I = have flown with a "Boost Referenced" adjustable fuel pressure regulator = from MSD.  As you know, it is desirable to keep the pressure differential between = the injector fuel rail pressure and the manifold pressure a constant for = best fuel injection control. 

 

I flew for several years thinking that since my = pressure regulator was manifold reference that it was indeed doing this.  = Then the light bulb came on - my fuel pressure holds rock-steady at 43 PSI - and = does not vary between idle and WOT!  This certainly implies that the = fuel pressure IS NOT varying as a function of manifold = pressure.

 

Then doing some recent research on fuel pressure = regulators, I noticed that some say they are "Boost Referenced" and = other's say "Vacuum/Boost Referenced".   My conclusion (which = may be incorrect)  is that while my pressure regulator is "Boost = Referenced" it is not "Vacuum Referenced".  The difference (If I = understand it correctly ) is that my regulator would increase fuel pressure IF it = ever encounter manifold pressure greater than ambient - since I am not used = forced induction that never happens - which in turn appears to be the reason I = never see the fuel pressure changing in response to manifold = "vacuum".

 

So my question to those who realllllllyyyyyy know - =  is it correct that for my NA 13B I need a fuel pressure regulator that = responses to manifold "Vacuum" or is the difference in description = between "vacuum referenced and boost referenced " just semantics in advertising?

 

Thanks

 

Ed

 

Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW

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