X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-05.southeast.rr.com ([24.25.9.104] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTP id 2196970 for flyrotary@lancaironline.net; Tue, 24 Jul 2007 16:49:34 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.104; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-05.southeast.rr.com (8.13.6/8.13.6) with SMTP id l6OKmZgq023347 for ; Tue, 24 Jul 2007 16:48:35 -0400 (EDT) Message-ID: <002501c7ce34$03c87ac0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: FUEL SYSTEM PRESSURE Date: Tue, 24 Jul 2007 16:48:39 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0022_01C7CE12.7C6CD970" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0022_01C7CE12.7C6CD970 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Mark,=20 I looked into installing the same kind of system early on, but did not. = I came to the conclusion (that for me and my type of flying) that this = system added no safety factor for me that running both pumps on take off = and landing did not do. If the "automatic" system failed to turn on your second pump (sensor = failure, wiring failure, relay failure, etc), you could spend precious = seconds figuring out what is wrong and hitting your manual override - I = presume it does have that. I would assume it also has some means of = letting you know that a pump has failed, warning light? tone? I always take off and land with both EFI high pressure pumps (and boost = pump) running. Once at cruise altitude I switch one EFI and the boost = pump off. If pump failure should happen in that regime of flight, I = have plenty of time to observe the decreasing fuel pressure and/or = stuttering engine and switch on the other pump. Not knocking that set up ( if designed and implemented well), but I have = a dislike of having anything critical being automatically done for me - = I'd rather do it myself. I never like talking cars either {:>) Ed ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Tuesday, July 24, 2007 4:24 PM Subject: [FlyRotary] Re: FUEL SYSTEM PRESSURE Dave,=20 You've got much more actual experience than I do, but I set my system = up like the Eggenfellner guys do. They use a pressure sensor coupled to = a relay to monitor the fuel pressures. The relay automatically turns on = the second efi pump if the pressure drops below a certain limit = (determined by the pressure sensor). That way the engine won't falter, = skip, run lean, etc. due to low fuel pressures. =20 The good thing about an efi system such as you have described is the = fuel in the fuel rails is always cool. Hot starts should be a = non-issue. =20 Mark S. =20 ------=_NextPart_000_0022_01C7CE12.7C6CD970 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Mark,
 
I looked into installing the same kind of system = early on,=20 but did not.  I came to the conclusion (that for me and my type of = flying)=20 that this system added no safety factor for me that running both pumps = on take=20 off and landing did not do.
 
  If the "automatic" system failed to turn = on your=20 second pump (sensor failure, wiring failure, relay failure, etc), you = could=20 spend precious seconds figuring out what is wrong and hitting your = manual=20 override - I presume it does have that.  I would assume it also has = some=20 means of letting you know that a pump has failed, warning light?=20 tone?
 
I always take off and land with both EFI high = pressure=20 pumps (and boost pump) running.  Once at cruise altitude I switch = one EFI=20 and the boost pump off.  If pump failure should happen in that = regime=20 of flight, I have plenty of time to observe the decreasing fuel pressure = and/or=20 stuttering engine and switch on the other pump.
 
Not knocking that set up ( if designed and = implemented=20 well), but I have a dislike of having anything critical being = automatically done=20 for me - I'd rather do it myself.  I never like talking cars either = {:>)
 
Ed
 
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Tuesday, July 24, 2007 = 4:24=20 PM
Subject: [FlyRotary] Re: FUEL = SYSTEM=20 PRESSURE

Dave,
You've got much more actual experience than I do, but I set my = system up=20 like the Eggenfellner guys do.  They use a pressure = sensor coupled=20 to a relay to monitor the fuel pressures.  The=20 relay automatically turns on the second efi pump if the=20 pressure drops below a certain limit (determined by the pressure=20 sensor).  That way the engine won't falter, skip, run lean, = etc. due=20 to low fuel pressures. 
 
The good thing about an efi system such as you have described is = the fuel=20 in the fuel rails is always cool.  Hot starts should be a=20 non-issue. 
 
Mark S.
 
=
 
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