X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-wy0-f180.google.com ([74.125.82.180] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4657776 for flyrotary@lancaironline.net; Wed, 29 Dec 2010 10:25:56 -0500 Received-SPF: pass receiver=logan.com; client-ip=74.125.82.180; envelope-from=rwstracy@gmail.com Received: by wyb28 with SMTP id 28so10076376wyb.25 for ; Wed, 29 Dec 2010 07:25:20 -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=drkBX6irMUn4tRNvxIQKrZdBduP5O+TdZz79TiIgdiw=; b=TQQDql0Oe4a09eruTUfrsoKaMXBwh5oCgeRW7JINtjS2z01xEsJH6l89PPFTthAZ6L O4oexgqcZLco6N29w3VSzxg1yJtnOmzSajQB2icXMgKCj8B42kz6udAQpKvuTEQMsEWz 1YmncrBemEJDxfIordamM9WpWtHJf1rhZDSCI= 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=pfsPyIOMbPGxXuflJAawDclTI6E20g2v5ChqyXcr2abrpHeGdBevcHktZdLMPGiPwj MQkXun4WL0mMHhz7LgQ+R/KVZYj8Y/bldqsBCN88c5y2hS8bsp9xvmiDxF+Dr9CSeEnF 5TknjwYaT7NGCDqfGqXjX4q1kPp7fWBBHCWwA= MIME-Version: 1.0 Received: by 10.216.17.3 with SMTP id i3mr11121224wei.80.1293636320530; Wed, 29 Dec 2010 07:25:20 -0800 (PST) Sender: rwstracy@gmail.com Received: by 10.216.200.158 with HTTP; Wed, 29 Dec 2010 07:25:20 -0800 (PST) In-Reply-To: References: Date: Wed, 29 Dec 2010 10:25:20 -0500 X-Google-Sender-Auth: 1S8tRlVHwDlJpeQrFcyjyZYtNgs Message-ID: Subject: Re: [FlyRotary] Re: Fuel rail pressure From: Tracy To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0016364c7c235a92d504988e2dad --0016364c7c235a92d504988e2dad Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable My Bad. The second test was to see if the temperature reading on the EM2 was the same with the sensor disconnected. The first test (sensor resistance to ground) could be done with the EM2 still connected or disconnected, either way. Tracy On Tue, Dec 28, 2010 at 10:47 PM, Bill Bradburry wrote: > Tracy, could you please clarify this for those of us not electrically > gifted? > > > > If you test between the sensor connector and ground with the wire > disconnected, you would be checking the resistance of the sensor wiring, > which, I assume, should be about 10 ohms? If higher, the sensor ground i= s > bad? > > If you test between the sensor wire going to the EM-2 and ground with the > wire disconnected you should get about 10 ohms as well??? Higher resista= nce > means bad connection or broken wire??? > > > > Bill B > > > ------------------------------ > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Tracy > *Sent:* Tuesday, December 28, 2010 5:24 PM > > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Fuel rail pressure > > > > Chris, > > The new settings on the EM2 fuel pressure calibration require the SW > sensor and the EM2 update. > > Your EM2 FP reading sounds like the sensor is either not connected or the > sensor is not grounded (not making connection to block). To test this > guess, With power OFF, measure the resistance to engine ground at the > sensor output. It should be about 10 ohms. If this is correct, disconn= ect > the sensor from the EC2 (at the sensor) and see if you get the same > reading. If so, the connection is probably broken somewhere. > > Tracy > > On Tue, Dec 28, 2010 at 5:04 PM, Chris Barber > wrote: > > Tracy/Group, > > > > I hate to be the village idiot (somebody's got to do it and Obama is in > Washington.....bad Chris...not a political forum....bad bad BAAAAD), but, > would I still be able to use the SW sensor with the mods you mention if I > have NOT been updated recently? Well, at least not in the last two months= . > > > > I have had fuel readings around 126 psi on the EM2 even though the gauge = on > the fuel pressure regulator read just a hair under 40psi. > > > > I have been meaning to buy a new VDO pressure sender but hesitated until = I > verified the wires...which I have now done. Should I use the VDO....or > transition to the SW? Is the update needed or does it just adjust the > settings as you described in your post? > > > > Now, on to the EGT reading problem and a desired solution and a few wire > run tweaks and I may be ready to call a DAR.....uh, or not ;-) > > > > Chris > ------------------------------ > > *From:* Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf > of Tracy [tracy@rotaryaviation.com] > > *Sent:* Tuesday, December 28, 2010 1:40 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: Fuel rail pressure > > Hello Brian, > Here is an excerpt from the updated EM2 installation guide. Note tha= t > this assumes that your EM2 has been updated since this change was develop= ed > (last 2 months or so). > > FUEL PRESSURE SENSOR > > 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. VDO at some point changed the design of these sensor and they ar= e > 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 i= s > 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 a= re > getting so hot that they are vaporizing I would think this would cause an > 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 pressur= e > regulator; which should bear about 40 psi engine off. That=92s true even = if > you call the e-shaft a crankshaftJ. > > Al > > > > > > > > > --0016364c7c235a92d504988e2dad Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable My Bad.=A0 The second test was to see if the temperature reading on the EM2= was the same with the sensor disconnected.
The first test (sensor resis= tance to ground) could be done with the EM2 still connected or disconnected= , either way.

Tracy=A0

On Tue, Dec 28, 2010 at 10:= 47 PM, Bill Bradburry <bbradburry@bellsouth.net> wrote:

Tracy, =A0could you please clarify th= is for those of us not electrically gifted?

=A0

If you test be= tween the sensor connector and ground with the wire disconnected, you would be checking the resistance= of the sensor wiring, which, I assume, should be about 10 ohms?=A0 If higher, the sensor ground is bad?

If you test be= tween the sensor wire going to the EM-2 and ground with the wire disconnected you should get about 10 o= hms as well???=A0 Higher resistance means bad connection or broken wire???

=A0

Bill B<= /font>

=A0

From: Rotary motors in aircraft [mailto:fl= yrotary@lancaironline.net] On Behalf Of Tracy
Sent: Tuesday, December 28= , 2010 5:24 PM


To: Rotary motors in aircraft
Subject: [FlyRotary] Re: F= uel rail pressure

=A0

Chris,


=A0 The new settings on the EM2 fuel pressure calibration require the SW sensor and the EM2 update.=A0

Your EM2 FP reading sounds like the sensor is either not connected or the sensor is not grounded (not making connection to block). =A0 To test this g= uess,=A0 With power OFF,=A0 measure the resistance to engine ground at the sensor output.=A0 It should be about 10 ohms.=A0 If this is correct,=A0 disconnect the sensor from the EC2 (at the sensor) and see if you get the s= ame reading.=A0 If so, the connection is probably broken somewhere.

Tracy

On Tue, Dec 28, 2010 at 5:04 PM, Chris Barber <cbarber@= texasattorney.net> wrote:

Tracy/Group,

=A0

I hate to be the=A0village idi= ot (somebody's got to do it and Obama is in Washington.....bad Chris...not a political forum....bad=A0bad BAAAAD), but, would I still be able to use the SW sensor with the=A0mods you mention if I have=A0NOT been updated recently? Well, at least not in the last two months.

=A0

I have had fuel readings aroun= d 126 psi on the=A0EM2 even though the gauge on the fuel pressure regulator read just a hair under 40psi.

=A0

I have been meaning to buy a n= ew=A0VDO pressure sender but hesitated until I verified the wires...which I have now done.=A0 Should I use the VDO....or transition to the SW?=A0 Is the update needed or does it just adjust the settings as you described in your post?

=A0

Now, on to the=A0EGT reading p= roblem and a desired solution and a few wire run tweaks=A0and I may be ready to call a DAR.....uh, or not ;-)

=A0

Chris

From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Tracy [tracy@rotary= aviation.com]


Sent: Tuesday, December 28= , 2010 1:40 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: F= uel rail pressure

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 this change was developed (last 2 months or so).

FUEL PRESSURE SENSOR<= /span>

=A0=A0=A0 The EM2 was= originally designed around VDO pressure sensors and the fuel pressure sensor was to be the same type as us= ed 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 These are available from Summit Racing as PN=A0 SWW-114875.=A0= =A0 To make 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 calibration 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 AM, <bktrub= @aol.com> wrote:

Tracy= ,

did you ever= find a suitable replacement fuel pressure sender? What are you using now?

=A0

Thanks,

Brian Trubee

=A0

-----Origina= l 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 installation so there is no fuel flow to flush vapor from the rails on hot startups.=A0 This arrangement is now used on most new cars.=A0 Even with this arrangement I have had no trouble with vapor lock.=A0=A0 Even if it should 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 othe= r 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 lo= ck. Running the fuel pump in such a case would cause coller fuel to flow throug= h the rail and back to the tank.

=A0

Brian Trubee

=A0

-----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 wh= en you are starting the engine you 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 vaporizin= g I would think this would cause an excess pressure in the fuel system and be very dangerous. =A0This is not a problem I have ever had in a car. =A0What is causing this besides poor ventilation?

The pressu= re in the fuel rail can never exceed the setting of the pressure regulator; which should bear about 40 ps= i engine off. That=92s true even if you call the e-shaft a crankshaft<= /font>J.

Al<= /font>

=A0

=A0

=A0

=A0


--0016364c7c235a92d504988e2dad--