X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-ww0-f50.google.com ([74.125.82.50] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4656900 for flyrotary@lancaironline.net; Tue, 28 Dec 2010 14:40:59 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.50; envelope-from=rwstracy@gmail.com Received: by wwf26 with SMTP id 26so9356987wwf.7 for ; Tue, 28 Dec 2010 11:40:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:sender:received :in-reply-to:references:date:x-google-sender-auth:message-id:subject :from:to:content-type; bh=vDYsZa3F8N5ChfOs83ygQQUn5xC+IK5UeRZKzBwW18Q=; b=JXMJYH2p8KNIGc6jTwxGY2Imb3dFxxMkggfDUDL1V8VILhp+qX7vO+4PrKY72Imywt 2I9zryfDHHknDE4HlMxpnL9auvwYqwkLIuxhEvj1qTioLba19FoGvPVxeW6qOLwDPJxS M+zz849VJ8dQF3CAqXh9XeYLJt4uqc3B+T7TQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=fO2fLVjbW5ffsG3GVNkzspYpNwJHM2bWGz0RRPT+pBtACr8u5p3Rs+SbeIFA59PTSX ziPdnMNpz+RIfSdh7GvIkKiUJys3KkHmIxgxyvJzL2jyRIbJGWbMRLbop9twDUgqLUpk zLqOP8aStIu0bO62UaYe8Bg6HaqUF8F9ol/1s= MIME-Version: 1.0 Received: by 10.216.61.202 with SMTP id w52mr17217797wec.110.1293565224376; Tue, 28 Dec 2010 11:40:24 -0800 (PST) Sender: rwstracy@gmail.com Received: by 10.216.200.158 with HTTP; Tue, 28 Dec 2010 11:40:24 -0800 (PST) In-Reply-To: References: Date: Tue, 28 Dec 2010 14:40:24 -0500 X-Google-Sender-Auth: 4ZzdMzpGzr4rdXXtloVJiuBjnjc Message-ID: Subject: Re: [FlyRotary] Re: Fuel rail pressure From: Tracy To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000e0ce0037ab15b7804987d9f9f --000e0ce0037ab15b7804987d9f9f Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hello Brian, Here is an excerpt from the updated EM2 installation guide. Note that this assumes that your EM2 has been updated since this change was developed (last 2 months or so). FUEL PRESSURE SENSOR The EM2 was originally designed around VDO pressure sensors and the fue= l pressure sensor was to be the same type as used for the Oil Pressure sensor= . VDO at some point changed the design of these sensor and they are no longer safe to use with Fuel (they begin leaking from the terminal end). The closest substitute is a Stewart Warner 114875. These are available from Summit Racing as PN *SWW-114875. **To make it fully compatible with the EM2 you must wire a 562 ohm resistor from the sensor output terminal to ground. This can be added near the sensor or near the EM2, which ever is most convenient. You must also set the Channel 13(mixture) Low limit value to 1 instead of 0. The calibration values for the Fuel pressure channel (12) should then be set to the following values: Scale factor =96 6.922 , LOW END OFFSET =96 0, SENSOR OFFSET ~ 963 , LOW ALARM LIMIT - ~28 , HIGH ALARM LIMIT -~55. * Tracy On Tue, Dec 28, 2010 at 12:10 AM, wrote: > Tracy, > did you ever find a suitable replacement fuel pressure sender? What are y= ou > using now? > > Thanks, > Brian Trubee > > > > -----Original Message----- > From: Tracy > To: Rotary motors in aircraft > Sent: Mon, Dec 27, 2010 4:30 pm > Subject: [FlyRotary] Re: Fuel rail pressure > > Just for another data point: > > I installed the fuel pressure regulator prior to the fuel rails in my 20B > installation so there is no fuel flow to flush vapor from the rails on ho= t > startups. This arrangement is now used on most new cars. Even with this > arrangement I have had no trouble with vapor lock. Even if it should > happen, the EC2/3 primer function would be able to vent the vapor from t= he > rails. > > This setup allows the use of a Floscan type fuel flow sensor with the EM2= /3 > since there is no return flow from the fuel rails. No big advantage othe= r > than being much easier to calibrate. > > Tracy > > On Mon, Dec 27, 2010 at 6:53 PM, wrote: > >> It seems to me that the fuel would have to be pretty hot for the vapor >> pressure to exceed 40 psi and cause vapor lock. Running the fuel pump in >> such a case would cause coller fuel to flow through the rail and back to= the >> tank. >> >> Brian Trubee >> >> >> >> -----Original Message----- >> From: Al Gietzen >> To: Rotary motors in aircraft >> Sent: Mon, Dec 27, 2010 3:49 pm >> Subject: [FlyRotary] Fuel rail pressure >> >> >> Also remember that when you are starting the engine you are starting it >> under a load. This is different then in a car config where in a car you= are >> starting it with no load attached to the crankshaft. If the fuel rails = are >> getting so hot that they are vaporizing I would think this would cause a= n >> excess pressure in the fuel system and be very dangerous. This is not a >> problem I have ever had in a car. What is causing this besides poor >> ventilation? >> The pressure in the fuel rail can never exceed the setting of the pressu= re >> regulator; which should bear about 40 psi engine off. That=92s true even= if >> you call the e-shaft a crankshaftJ. >> Al >> >> > > --000e0ce0037ab15b7804987d9f9f Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hello Brian,
=A0=A0 Here is an excerpt from the updated EM2 installation= guide.=A0=A0 Note that this assumes that your EM2 has been updated since t= his change was developed (last 2 months or so).

FUEL PRESSURE SENSOR

=A0=A0=A0 The EM2 was originally designed around VDO pressure sensors and the = fuel pressure sensor was to be the same type as used for the Oil Pressure sensor.=A0 VDO at some point changed the design of these sensor and they are no longer=A0 safe to use with Fuel (they begin leaking from the terminal end).=A0=A0 The closest substitute is a Stewart Warner=A0 114875.=A0=A0=A0=A0=A0 <= /span>These are available from Summit Racing as PN=A0 SWW-114875.=A0=A0 To mak= e it fully compatible with the EM2 you must wire a 562 ohm resistor from the sensor output terminal to ground.=A0=A0 This can be added near the sensor or near the EM2, which ever is most convenient.=A0=A0=A0 You must also set the Channel 13(mixture)=A0 Low limit value to 1 instead of 0.=A0 The calibrat= ion values for the Fuel pressure channel (12) should then be set to the following values:= =A0 Scale factor =96 6.922 , LOW END OFFSET =96 0, SENSOR OFFSET ~ 963 , LOW ALARM LIMIT - ~28 , HIGH ALARM LIMIT -~55.


Tracy

On Tue, Dec 28, 2010 at 12:10 A= M, <bktrub@aol.com<= /a>> wrote:
Tracy,
did you ever find a suitable replacement fuel pressure sender? What ar= e you using now?
=A0
Thanks,
Brian Trubee



-----Original Message-----
From: Tracy <tracy@rotaryaviation.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Dec 27, 2010 4:30 pm
Subject: [FlyRotary] Re: Fuel rail pressure

Just for another data point:

I installed the fuel pressure regulator prior to the fuel rails in my 20B i= nstallation so there is no fuel flow to flush vapor from the rails on hot s= tartups.=A0 This arrangement is now used on most new cars.=A0 Even with thi= s arrangement I have had no trouble with vapor lock.=A0=A0 Even if it shoul= d happen, the EC2/3=A0 primer function would be able to vent the vapor from= the rails.

This setup allows the use of a Floscan type fuel flow sensor with the EM2/3= since there is no return flow from the fuel rails.=A0 No big advantage oth= er than being much easier to calibrate.

Tracy

On Mon, Dec 27, 2010 at 6:53 PM, <bktrub@aol.com> wrote:
It seems to me that the fuel would have to be pretty hot for the vapor= pressure to exceed 40 psi and cause vapor lock. Running the fuel pump in s= uch a case would cause coller fuel to flow through the rail and back to the= tank.
=A0
Brian Trubee



-----Original Message-----
From: Al Gietzen <ALVentures@cox.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Mon, Dec 27, 2010 3:49 pm
Subject: [FlyRotary] Fuel rail pressure

=A0
Also remember that when you are starting the engine y= ou are starting it under a load. =A0This is different then in a car config = where in a car you are starting it with no load attached to the crankshaft.= =A0If the fuel rails are getting so hot that they are vaporizing I would t= hink this would cause an excess pressure in the fuel system and be very dan= gerous. =A0This is not a problem I have ever had in a car. =A0What is causi= ng this besides poor ventilation?
The pressure in the fuel rail can never exceed the s= etting of the pressure regulator; which should bear about 40 psi engine off= . That=92s true even if you call the e-shaft a crankshaftJ.
Al
=A0


--000e0ce0037ab15b7804987d9f9f--