Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2.8) with ESMTP id 617335 for flyrotary@lancaironline.net; Sat, 22 Jan 2005 08:42:40 -0500 Received-SPF: none receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.rr.com [24.74.185.127]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j0MDg6Ci025240 for ; Sat, 22 Jan 2005 08:42:08 -0500 (EST) Message-ID: <000801c50088$77819360$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Manifold-Reference Fuel Pressure was [FlyRotary] Re: Fuel Injector Sizing Date: Sat, 22 Jan 2005 08:44:16 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0005_01C5005E.8E6B4E10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0005_01C5005E.8E6B4E10 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Re: Fuel Injector SizingI agree with your statement, = Buly. Ideally if the pressure differential between fuel rail and = manifold is kept constant by use of a manifold reference then that would = imply that the fuel pressure should vary to compensate for different = manifold pressure. However, my fuel pressure is rock steady and this is = the second manifold-referenced fuel pressure regulator I have used with = no difference. So either my manifold-reference fuel pressure regulator = isn't or I am misunderstanding what they are suppose to do. But, that is my experience. How about others of you flying what is your = experience with fuel pressure??? Does it vary? The variance corresponds = to what?? Thanks Ed A ----- Original Message -----=20 From: Bulent Aliev=20 To: Rotary motors in aircraft=20 Sent: Saturday, January 22, 2005 8:16 AM Subject: [FlyRotary] Re: Fuel Injector Sizing I'll check it again Ed, but mine varies. I thought the whole idea of = being MAP referenced is to react to the MAP changes? Other ways we it = can keep the pressure constant without the MAP reff. Buly On 1/22/05 7:42 AM, "Ed Anderson" wrote: Hi Buly, Actually, I have a manifold referenced pressure regulator (which if = I understand the concept) attempts to keep the pressure differential = between the fuel side and manifold side of the injector constant. = However, Varying engine manifold pressure (varying throttle opening) = does not appear to have any affect on my fuel pressure. It sits rock = steady at 40 psi with one pump and goes up to 43 psi with both running = regardless of throttle position. I would expect that as manifold = pressure rises from opening the throttle that the fuel pressure would = rise to keep the pressure differential constant - but, if that is indeed = happening, I can not detect it. Ed A =20 ----- Original Message -----=20 =20 From: Bulent Aliev =20 =20 To: Rotary motors in aircraft = =20 =20 Sent: Friday, January 21, 2005 7:57 PM =20 Subject: [FlyRotary] Re: Fuel Injector Sizing =20 On 1/21/05 6:37 PM, "Ed Anderson" = wrote: =20 George, my fuel pressure gauge reads between 40 and 43 psi = depending on whether I have one or both pumps on. I fly with 40 psi = (one pump). My pump (with no flow) will give a pressure of 80 psi, = but a regulator keeps it at 40-43 psi. I generally check my pumps for = their no-flow pressure and have noticed over the 6 years that the = pressure of the main pump has decreased from 80 psi to 60 psi - so = getting near replacement time. The spare pump still produces 80 psi - = less wear as it is normally only on for take off and landing. Ed A Hi Ed, do you set your fuel pressure without the engine running = or with? The MAP varies the FP while running, so I Assume 37 psi = without engine running would be the benchmark? Buly=20 ------=_NextPart_000_0005_01C5005E.8E6B4E10 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] Re: Fuel Injector Sizing
I agree with your statement, = Buly.  Ideally if=20 the pressure differential between fuel rail and manifold is kept = constant=20 by use of a manifold reference then that would imply that the fuel = pressure=20 should vary to compensate for different manifold pressure.  = However, my=20 fuel pressure is rock steady and this is the second manifold-referenced = fuel=20 pressure regulator I have used with no difference.  So either my=20 manifold-reference fuel pressure regulator isn't or I am = misunderstanding what=20 they are suppose to do.
 
But, that is my experience.  How = about others=20 of you flying what is your experience with fuel pressure???  Does = it vary?=20 The variance corresponds to what??
 
Thanks
 
 
Ed A
----- Original Message -----
From:=20 Bulent=20 Aliev
Sent: Saturday, January 22, = 2005 8:16=20 AM
Subject: [FlyRotary] Re: Fuel = Injector=20 Sizing

I=92ll check it=20 again Ed, but mine varies. I thought the whole idea of being MAP = referenced is=20 to react to the MAP changes? Other ways we it can keep the pressure = constant=20 without the MAP reff.
Buly


On 1/22/05 7:42 AM, "Ed = Anderson"=20 <eanderson@carolina.rr.com&g= t;=20 wrote:
Hi=20 Buly,

Actually, I=20 have a manifold referenced pressure regulator (which if I understand = the=20 concept) attempts to keep the pressure differential between the fuel = side=20 and manifold side of the injector constant. However, Varying engine = manifold=20 pressure (varying throttle opening) does not appear to have any = affect on my=20 fuel pressure.  It sits rock steady at 40 psi with one pump and = goes up=20 to 43 psi with both running regardless of throttle position.  I = would=20 expect that as manifold pressure rises from opening the throttle = that the=20 fuel pressure would rise to keep the pressure differential constant = - but,=20 if that is indeed happening, I can not detect it.

Ed A

 

-----=20 Original Message -----
 
From:  Bulent =  Aliev=20 <mailto:atlasyts@bellsouth.net&= gt;=20  
 
To: Rotary motors in aircraft <mailto:flyrotary@lancairo= nline.net>=20  
 
Sent: Friday, January 21, 2005 7:57=20  PM
 
Subject: [FlyRotary] Re: Fuel = Injector=20  Sizing
 

On 1/21/05  6:37 PM, "Ed = Anderson"=20 <eanderson@carolina.rr.com>=20  wrote:

 
George, my=20 fuel  pressure gauge reads between 40 and 43 psi depending = on=20 whether I have one  or both pumps on.  I fly with 40 = psi (one=20 pump).   My pump  (with no flow) will give a = pressure of=20 80 psi, but a regulator keeps it at  40-43 psi.  I = generally=20 check my pumps for their no-flow pressure and  have noticed = over=20 the 6 years that the pressure of the main pump has =  decreased from=20 80 psi to 60 psi - so getting near replacement time. =   The=20 spare pump still produces 80 psi - less wear as it is normally=20  only on for take off and landing.

Ed=20  A

Hi Ed, do you set your fuel pressure without = the engine=20  running or with? The MAP varies the FP while running, so I = Assume 37=20 psi  without engine  running would be the = benchmark?
Buly=20

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