X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.129.170.194] (HELO VIRCOM1.fcdata.private) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4657019 for flyrotary@lancaironline.net; Tue, 28 Dec 2010 17:05:26 -0500 Received-SPF: none receiver=logan.com; client-ip=64.129.170.194; envelope-from=cbarber@texasattorney.net Received: from FCD-MAIL06.FCDATA.PRIVATE ([2002:101:102::101:102]) by FCD-MAIL05.FCDATA.PRIVATE ([fe80::809d:a06e:5913:452e%15]) with mapi id 14.01.0218.012; Tue, 28 Dec 2010 16:01:41 -0600 From: Chris Barber To: Rotary motors in aircraft Subject: RE: [FlyRotary] Re: Fuel rail pressure Thread-Topic: [FlyRotary] Re: Fuel rail pressure Thread-Index: AQHLpscxueZR92d0vEKbonAIyErDmJO2ZXaI Date: Tue, 28 Dec 2010 22:04:58 +0000 Message-ID: <2D41F9BF3B5F9842B164AF93214F3D3034CE46A7@FCD-MAIL06.FCDATA.PRIVATE> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [166.139.76.11] Content-Type: multipart/alternative; boundary="_000_2D41F9BF3B5F9842B164AF93214F3D3034CE46A7FCDMAIL06FCDATA_" MIME-Version: 1.0 --_000_2D41F9BF3B5F9842B164AF93214F3D3034CE46A7FCDMAIL06FCDATA_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable Tracy/Group, I hate to be the village idiot (somebody's got to do it and Obama is in Was= hington.....bad Chris...not a political forum....bad bad BAAAAD), but, woul= d 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 tra= nsition to the SW? Is the update needed or does it just adjust the setting= s as you described in your post? Now, on to the EGT reading problem and a desired solution and a few wire ru= n 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 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 sens= or. VDO at some point changed the design of these sensor and they are no l= onger 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 adde= d near the sensor or near the EM2, which ever is most convenient. You mu= st also set the Channel 13(mixture) Low limit value to 1 instead of 0. Th= e 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, SE= NSOR OFFSET ~ 963 , LOW ALARM LIMIT - ~28 , HIGH ALARM LIMIT -~55. Tracy On Tue, Dec 28, 2010 at 12:10 AM, > w= rote: Tracy, did you ever find a suitable replacement fuel pressure sender? What are you= 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 i= nstallation so there is no fuel flow to flush vapor from the rails on hot s= tartups. This arrangement is now used on most new cars. Even with this ar= rangement 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 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. No big advantage other= than being much easier to calibrate. Tracy On Mon, Dec 27, 2010 at 6:53 PM, > wr= ote: It seems to me that the fuel would have to be pretty hot for the vapor pres= sure 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 und= er a load. This is different then in a car config where in a car you are s= tarting 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 an e= xcess pressure in the fuel system and be very dangerous. This is not a pro= blem I have ever had in a car. What is causing this besides poor ventilati= on? The pressure in the fuel rail can never exceed the setting of the pressure = regulator; which should bear about 40 psi engine off. That=92s true even if= you call the e-shaft a crankshaft:). Al --_000_2D41F9BF3B5F9842B164AF93214F3D3034CE46A7FCDMAIL06FCDATA_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable

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 ba= d BAAAAD), but, would I still be able to use th= e SW sensor with the mods you mention if I have NOT been updated recently? Well, at least not in th= e last two months.

 

I have had fuel readings around 126 psi on the EM2 ev= en though the gauge on the fuel pressure regulator read just a hair under 4= 0psi.

 

I have been meaning to buy a new VDO pressure sender = but hesitated until I verified the wires...which I have now done.  Sho= uld I use the VDO....or transition to the SW?  Is the up= date needed or does it just adjust the settings as you described in your post?

 

Now, on to the EGT reading problem and a desired solu= tion 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.&nb= sp;  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 = fuel pressure sensor was to be the same type as used for the Oil Pressure s= ensor.  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 ava= ilable 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 mos= t convenient.    You must also set the Channel 13(mixture)  Low lim= it value to 1 instead of 0.  The calibration values for the Fuel pressure channel (12) should the= n 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, <bktrub@aol.com<= /a>> wrote:
Tracy,
did you ever find a suitable replacement fuel pressure sender? What ar= e you using now?
 
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.  This arrangement is now used on most new cars.  Even wi= th this arrangement I have had no trouble with vapor lock.   Even if it should happen, the EC2/3  pri= mer 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.  No big advantage = other 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.
 
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

 
A= lso remember that when you are starting the engine you are starting it unde= r a load.  This is different then in a car config where in a car you a= re starting it with no load attached to the crankshaft.  If the fuel rails are getting so hot that they are vapor= izing 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 set= ting 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
 


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