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Fuel Flow

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billderou(at)yahoo.com
Guest

Posted: Tue Jan 06, 2009 10:22 am Post subject: Fuel Flow

Guys-

 I have beat my brain over this issue with no success. Can anyone provide a suitable answer?

  

 When I turn on my electrical fuel pump during cruise the fuel flow will increase approx 10%.

  

 I have the standard Vans setup. There are no leaks nor fuel smells. No metric nor sound on the engine changes (although maybe if I looked carefully the airspeed would increase slowly).

  

 Thanks,

 Bill DeRouchey

 N939SB, flying

  

 [quote][b]

rene(at)felker.com
Guest

Posted: Tue Jan 06, 2009 10:50 am Post subject: Fuel Flow

Yes, turbulence in the fuel line caused by the fuel pump.  Same thing for me.  The only solution would be to move the sensor……  

   

Rene' Felker  

RV-10 N423CF Flying  

801-721-6080    

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Bill DeRouchey

 Sent: Tuesday, January 06, 2009 11:22 AM

 To: rv10-list(at)matronics.com

 Subject: Fuel Flow   

  

              

Guys-   

      

I have beat my brain over this issue with no success. Can   anyone provide a suitable answer?   

      

    

      

When I turn on my electrical fuel pump during cruise the   fuel flow will increase approx 10%.   

      

    

      

I have the standard Vans setup. There are no leaks nor   fuel smells. No metric nor sound on the engine changes (although maybe if I   looked carefully the airspeed would increase slowly).   

      

    

      

Thanks,   

      

Bill DeRouchey   

      

N939SB, flying   

      

    

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       [quote][b]

Dave(at)AirCraftersLLC.co
Guest

Posted: Tue Jan 06, 2009 10:50 am Post subject: Fuel Flow

Bill,

  

 Here's my untested, unscientific, uneverything  opinion:

  

 In the stock location, the cube gets fuel  pushed and pulled through it.  The boost pump is essentially a steady  pressure on one side of the vane, but I suspect that the mechanical diaphragm  pump is pulling in pulses on the other side.  As the vanes in the cube  rotate, they see a steady pressure on the downstream side from the boost pump,  but they get accelerated when the mechanical pump makes a stroke and lowers the  pressure on the upstream side.  So the vane spins a little faster when it  sees the larger differential pressure.  Of course there has to be some  pressure difference or the vane wouldn't move, but I think the pulses from the  upstream pump are the cause.

  

 A few months ago we moved a customer's  sender from the stock location to the "approved" location between the servo and  the spider.  The problem disappeared.  I plan on moving mine,  too.

  

  Dave Saylor

 AirCrafters LLC

 140 Aviation Way

 Watsonville, CA 

 831-722-9141

 831-750-0284 CL

 www.AirCraftersLLC.com



  

  

  

  

 



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Bill  DeRouchey

Sent: Tuesday, January 06, 2009 10:22 AM

To:  rv10-list(at)matronics.com

Subject: Fuel  Flow

 

                   Guys-

       I have beat my brain over this issue with no success. Can anyone        provide a suitable answer?

        

       When I turn on my electrical fuel pump during cruise the fuel flow        will increase approx 10%.

        

       I have the standard Vans setup. There are no leaks nor fuel smells.        No metric nor sound on the engine changes (although maybe if I looked        carefully the airspeed would increase slowly).

        

       Thanks,

       Bill DeRouchey

       N939SB, flying

        

[quote]



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href='3D"http://www.matronics.com/Navigator?RV10-List"'>http://www.matronics.com/Navigator?RV10-List

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[b]

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Tue Jan 06, 2009 10:59 am Post subject: Fuel Flow

I've always heard it's cavitation, but I have no proof.



Tim Olson - RV-10 N104CD - Flying

do not archive

Bill DeRouchey wrote:

 	  Quote: 	
		   Guys-

 I have beat my brain over this issue with no success. Can anyone provide 

 a suitable answer?

  

 When I turn on my electrical fuel pump during cruise the fuel flow will 

 increase approx 10%.

  

 I have the standard Vans setup. There are no leaks nor fuel smells. No 

 metric nor sound on the engine changes (although maybe if I looked 

 carefully the airspeed would increase slowly).

  

 Thanks,

 Bill DeRouchey

 N939SB, flying

jesse(at)saintaviation.co
Guest

Posted: Tue Jan 06, 2009 11:26 am Post subject: Fuel Flow

This has been discussed a fair bit on the list in the past.  In the stock location there is always an increase in reading even though the actual flow doesn't necessarily change.  In talking to the floscan people they said it has something to do with the pulses sent out by the electric pump that somehow makes it read higher.  It may be cavitation as Tim mentioned, but you don't have to sweat it (unless you smell fuel when it's on, of course, or find a leak somewhere).  That section of line is not under high pressure unless the boost pump is on, so a poor seal could leak when the pump is on and not when it is off, but you would know if it was.

 Jesse Saint

Saint Aviation, Inc.

jesse(at)saintaviation.com (jesse(at)saintaviation.com)

Cell: 352-427-0285

Fax: 815-377-3694



 



On Jan 6, 2009, at 1:22 PM, Bill DeRouchey wrote:

 	  Quote: 	
		  Guys-

 I have beat my brain over this issue with no success. Can anyone provide a suitable answer?

  

 When I turn on my electrical fuel pump during cruise the fuel flow will increase approx 10%.

  

 I have the standard Vans setup. There are no leaks nor fuel smells. No metric nor sound on the engine changes (although maybe if I looked carefully the airspeed would increase slowly).

  

 Thanks,

 Bill DeRouchey

 N939SB, flying

  

  	  Quote: 	
		  

3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

href="3D"http://www.matronics.com/Navigator?RV10-List"">http://www.matronics.com/Navigator?RV10-List

3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

href="3D"http://forums.matronics.com"">http://forums.matronics.com

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 [quote][b]

Kellym

Joined: 10 Jan 2006
Posts: 1705
Location: Sun Lakes AZ

Posted: Tue Jan 06, 2009 12:00 pm Post subject: Fuel Flow

Hmm, on certified aircraft with Bendix RSA injection systems the sending 

unit cube is normally installed between the mechanical pump and the fuel 

servo. Given the line to the spyder is shorter and vertical, finding a 

location with enough straight run would be a challenge.

Usually recommended in the middle of the line between the pump and 

servo, to give it some vibration isolation, as well as straight hose 

sections before and after the cube.

The sending unit used on systems like Continentals is different because 

of the fuel return line, and I believe most of those are installed 

between the servo and spyder.

Kelly



Dave Saylor wrote:

 	  Quote: 	
		   Bill,

  

 Here's my untested, unscientific, uneverything opinion:

  

 In the stock location, the cube gets fuel pushed and pulled through 

 it.  The boost pump is essentially a steady pressure on one side of 

 the vane, but I suspect that the mechanical diaphragm pump is pulling 

 in pulses on the other side.  As the vanes in the cube rotate, they 

 see a steady pressure on the downstream side from the boost pump, but 

 they get accelerated when the mechanical pump makes a stroke and 

 lowers the pressure on the upstream side.  So the vane spins a little 

 faster when it sees the larger differential pressure.  Of course there 

 has to be some pressure difference or the vane wouldn't move, but I 

 think the pulses from the upstream pump are the cause.

  

 A few months ago we moved a customer's sender from the stock location 

 to the "approved" location between the servo and the spider.  The 

 problem disappeared.  I plan on moving mine, too.

  

 Dave Saylor

 AirCrafters LLC

 140 Aviation Way

 Watsonville, CA

 831-722-9141

 831-750-0284 CL

 www.AirCraftersLLC.com

  

  

  

  



 ------------------------------------------------------------------------

 *From:* owner-rv10-list-server(at)matronics.com 

 [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of *Bill 

 DeRouchey

 *Sent:* Tuesday, January 06, 2009 10:22 AM

 *To:* rv10-list(at)matronics.com

 *Subject:* Fuel Flow



 Guys-

 I have beat my brain over this issue with no success. Can anyone 

 provide a suitable answer?

  

 When I turn on my electrical fuel pump during cruise the fuel flow 

 will increase approx 10%.

  

 I have the standard Vans setup. There are no leaks nor fuel smells. No 

 metric nor sound on the engine changes (although maybe if I looked 

 carefully the airspeed would increase slowly).

  

 Thanks,

 Bill DeRouchey

 N939SB, flying

  



 *



 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

 href='3D"http://www.matronics.com/Navigator?RV10-List"'>http://www.matronics.com/Navigator?RV10-List

 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

 href='3D"http://forums.matronics.com"'>http://forums.matronics.com

 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

 href='3D"http://www.matronics.com/contribution"'>http://www.matronics.com/contribution

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 *

 *

 *

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD

msausen

Joined: 25 Oct 2007
Posts: 559
Location: Appleton, WI USA

Posted: Tue Jan 06, 2009 12:33 pm Post subject: Fuel Flow

I believe that is why Matt developed this…..  

   

http://www.matronics.com/fuelchec/dampener.html  

   

Michael  

       

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Tuesday, January 06, 2009 1:25 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Fuel Flow   

  

  

   

This has been discussed a fair bit on the list in the past.  In the stock location there is always an increase in reading even though the actual flow doesn't necessarily change.  In talking to the floscan people they said it has something to do with the pulses sent out by the electric pump that somehow makes it read higher.  It may be cavitation as Tim mentioned, but you don't have to sweat it (unless you smell fuel when it's on, of course, or find a leak somewhere).  That section of line is not under high pressure unless the boost pump is on, so a poor seal could leak when the pump is on and not when it is off, but you would know if it was.      

         

Jesse Saint  

    

Saint Aviation, Inc.  

    

jesse(at)saintaviation.com (jesse(at)saintaviation.com)  

    

Cell: 352-427-0285  

    

Fax: 815-377-3694  

  

  

  

       

On Jan 6, 2009, at 1:22 PM, Bill DeRouchey wrote:  

  



 

              

Guys-   

      

I have beat my brain over this issue with no success. Can   anyone provide a suitable answer?   

      

    

      

When I turn on my electrical fuel pump during cruise the   fuel flow will increase approx 10%.   

      

    

      

I have the standard Vans setup. There are no leaks nor   fuel smells. No metric nor sound on the engine changes (although maybe if I   looked carefully the airspeed would increase slowly).   

      

    

      

Thanks,   

      

Bill DeRouchey   

      

N939SB, flying   

      

    

        

  

  

  [quote] [b]

ron.mcgann(at)baesystems.
Guest

Posted: Tue Jan 06, 2009 1:51 pm Post subject: Fuel Flow

Curiosity aroused here.  Apart from when switching  tanks, and assuming the mechanical (engine driven) pump is working ok, under  what conditions would you be using the electric fuel pump in cruise?  If  the mechanical pump goes u/s, and the electrical pump is now the main fuel pump,  is there still a problem with overreading flow?

  

 you know - enquiring minds etc . . .  

  

 cheers

 Ron

 -187, fiddly bits and  paperwork

  

 Do not  archive



 [quote]         From: owner-rv10-list-server(at)matronics.com    [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of RV Builder    (Michael Sausen)

Sent: Wednesday, 7 January 2009 7:02    AM

To: rv10-list(at)matronics.com

Subject: RE: RV10-List:    Fuel Flow 

   

      

I    believe that is why Matt developed this…..   

    

http://www.matronics.com/fuelchec/dampener.html   

    

Michael   

          

From:    owner-rv10-list-server(at)matronics.com    [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse    Saint

Sent: Tuesday, January 06, 2009 1:25 PM

To:    rv10-list(at)matronics.com

Subject: Re: Fuel Flow    



   

    

This has been discussed a fair bit on the list in the past.     In the stock location there is always an increase in reading even though    the actual flow doesn't necessarily change.  In talking to the floscan    people they said it has something to do with the pulses sent out by the    electric pump that somehow makes it read higher.  It may be cavitation as    Tim mentioned, but you don't have to sweat it (unless you smell fuel when it's    on, of course, or find a leak somewhere).  That section of line is not    under high pressure unless the boost pump is on, so a poor seal could leak    when the pump is on and not when it is off, but you would know if it    was.         

             

Jesse    Saint

      

Saint    Aviation, Inc.

      

jesse(at)saintaviation.com (jesse(at)saintaviation.com)

      

Cell:    352-427-0285

      

Fax:    815-377-3694

   

          

On Jan 6, 2009, at 1:22 PM, Bill DeRouchey    wrote:

   

                                      

Guys-

                  

I have beat my brain over this issue with no success.          Can anyone provide a suitable answer?

                  

 

                  

When I turn on my electrical fuel pump during cruise          the fuel flow will increase approx 10%.

                  

 

                  

I have the standard Vans setup. There are no leaks          nor fuel smells. No metric nor sound on the engine changes (although          maybe if I looked carefully the airspeed would increase          slowly).

                  

 

                  

Thanks,

                  

Bill DeRouchey

                  

N939SB, flying

                  

 



 	  Quote: 	
		   



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[b]

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Tue Jan 06, 2009 1:59 pm Post subject: Fuel Flow

Accumulators are a valued asset.  Thanks Michael for reminding me (all of us) of Matt's contribution.  Its use does not mitigate correct placement of the sensor in the scheme of things.

  

 And kudo's to Tim for the use of the word "cavitation".  We see lots of problems with low fluid level, fluid contaminates, pump impeller function and cavitation.  Correct fuel pressure indication is a Valued thing.  It reminded me how inefficient air impellers are in grand design of moving air (to which there is little direction connection to this thread).

  



  John Cox



 #40600

  From: owner-rv10-list-server(at)matronics.com on behalf of RV Builder (Michael Sausen)

Sent: Tue 1/6/2009 12:31 PM

To: rv10-list(at)matronics.com

Subject: RE: Fuel Flow 

   

I believe that is why Matt developed this….. 

  

http://www.matronics.com/fuelchec/dampener.html 

  

Michael 

   

 



 [quote][b]

pascal(at)rv10builder.net
Guest

Posted: Tue Jan 06, 2009 6:04 pm Post subject: Fuel Flow

Not sure how I missed that the floscan is in the wrong  location the last couple of years.. 

 Dave;

 I don’t see any room to move my floscan from the Van's plans  location to near the spider, how did you make it so it all fits?

 Thanks!

 Pascal

  



  From: Dave Saylor (Dave(at)AirCraftersLLC.com) 

 Sent: Tuesday, January 06, 2009 10:49 AM

 To: rv10-list(at)matronics.com (rv10-list(at)matronics.com) 

 Subject: RE: Fuel Flow

 



 Bill,

  

 Here's my untested, unscientific, uneverything  opinion:

  

 In the stock location, the cube gets fuel  pushed and pulled through it.  The boost pump is essentially a steady  pressure on one side of the vane, but I suspect that the mechanical diaphragm  pump is pulling in pulses on the other side.  As the vanes in the cube  rotate, they see a steady pressure on the downstream side from the boost pump,  but they get accelerated when the mechanical pump makes a stroke and lowers the  pressure on the upstream side.  So the vane spins a little faster when it  sees the larger differential pressure.  Of course there has to be some  pressure difference or the vane wouldn't move, but I think the pulses from the  upstream pump are the cause.

  

 A few months ago we moved a customer's  sender from the stock location to the "approved" location between the servo and  the spider.  The problem disappeared.  I plan on moving mine,  too.

  

  Dave Saylor

 AirCrafters LLC

 140 Aviation Way

 Watsonville, CA 

 831-722-9141

 831-750-0284 CL

 www.AirCraftersLLC.com



  

  

  

  

 



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Bill  DeRouchey

Sent: Tuesday, January 06, 2009 10:22 AM

To:  rv10-list(at)matronics.com

Subject: Fuel  Flow

 

                   Guys-

       I have beat my brain over this issue with no success. Can anyone        provide a suitable answer?

        

       When I turn on my electrical fuel pump during cruise the fuel flow        will increase approx 10%.

        

       I have the standard Vans setup. There are no leaks nor fuel smells.        No metric nor sound on the engine changes (although maybe if I looked        carefully the airspeed would increase slowly).

        

       Thanks,

       Bill DeRouchey

       N939SB, flying

        

[quote]



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[b]

orchidman

Joined: 10 Jul 2006
Posts: 277
Location: Oklahoma City - KRCE

Posted: Tue Jan 06, 2009 7:18 pm Post subject: Re: Fuel Flow

 	  pascal(at)rv10builder.net wrote: 	
		  Not sure how I missed that the floscan is in the wrong  location the last couple of years.. 

 Dave;

 I donï¿½t see any room to move my floscan from the Van's plans  location to near the spider, how did you make it so it all fits?

 Thanks!

 Pascal

  	


Pascal,

Go to Robs forum at

http://www.advanced-flight-systems.com/forum/viewtopic.php?t=454

about the 4th message you will find a picture.  I am currently in the process of doing the same thing but it will be another couple weeks before I will have it finished so I can't get any pictures now.

Basically you place the transducer between the servo and the spider.  If you are not doing an electronic ignition, you could also place the transducer on top of the engine just before it enters the spider.

_________________
Gary Blankenbiller
RV10 - # 40674
(N2GB Flying)

timrvator(at)comcast.net
Guest

Posted: Tue Jan 06, 2009 7:27 pm Post subject: Fuel Flow

I had this problem on my RV-6A.  Problem was caused by the fuel pulses from the electric pump.  Solved the problem by putting a Fram G3 clear plastic fuel filter between the electric fuel pump and the fuel flow sensor.  Then I "burped" air into the Fram G3 so that it (the filter) was 1/2 full of air.  The air dampens the pressure pulses, now flow meter reads essentially the same (in steady state) with or without the electric boost pump engaged.  (Out of an abundance of caution I poked a hole in the fuel filter's internal baffle to provide an alternate fluid path in case "crap" or ice crystals ever accumulate in the filter elements.)

 

 I found that during aerobatics the Fram G3 would sometimes loose all it's air (it would end up being full of fuel).  In that situation, on the ground with the engine running, I'd "burp" more air into the filter by setting the fuel selector at "off" while removing that little brass plug that blocks the fuel selector's "off" input port. 

 

 Matronics sells a device that will accomplish the same thing.  See http://www.matronics.com/fuelchec/dampener.html.  I'll probably use the Matronics device if I see the problem in my RV-10, because I'm not comfortable operating a Fram G3 at high fuel pressure.  

 

 Tim

  	  Quote: 	
		  -- 

Tim Lewis -- HEF (Manassas, VA)

RV-6A N47TD -- 1000 hrs

RV-10 #40059 under construction 	
 

 

 Bill DeRouchey wrote: [quote]                                 Guys-

         I have beat my brain over this issue with no success. Can anyone provide a suitable answer?

          

         When I turn on my electrical fuel pump during cruise the fuel flow will increase approx 10%.

          

         I have the standard Vans setup. There are no leaks nor fuel smells. No metric nor sound on the engine changes (although maybe if I looked carefully the airspeed would increase slowly).

          

         Thanks,

         Bill DeRouchey

         N939SB, flying

          

                            	  Quote: 	
		  



 href="3D%22http://www.matronics.com/Navigator?RV10-List%22">http://www.matronics.com/Navigator?RV10-List

 href="3D%22http://forums.matronics.com%22">http://forums.matronics.com

 href="3D%22http://www.matronics.com/contribution%22">http://www.matronics.com/contribution



	
 [b]

msausen

Joined: 25 Oct 2007
Posts: 559
Location: Appleton, WI USA

Posted: Wed Jan 07, 2009 6:28 am Post subject: Fuel Flow

Pascal,  

   

  I wouldn’t worry about it much, lots of people have put it in the stock location.  If the error is really apparent, I would try Matt’s dampener before trying to relocate it.    

   

Michael  

       

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of pascal

 Sent: Tuesday, January 06, 2009 8:03 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Fuel Flow  

  

  

     

Not sure how I missed that the floscan is in the wrong location the last couple of years..   

    

Dave;  

    

I don’t see any room to move my floscan from the Van's plans location to near the spider, how did you make it so it all fits?  

    

Thanks!  

    

Pascal  

  

      [quote][b]

billderou(at)yahoo.com
Guest

Posted: Wed Jan 07, 2009 7:12 pm Post subject: Fuel Flow

Good comments from everyone. I guess I was asleep last year when this was discussed. I read about Matts air-ball but since the stock tubing is straight before and after the flow sensor I thought it applied to a non-stock configuration.



The only reason I had the electrical fuel pump on in cruise was to test the condition with the autopilot on so I could focus on the abnormality.



It would seem that any modification or relocation of the fuel flow sensor could upset the calibration - so it must be recalibrated after the final configuration is in place. It is very important to me that this value is correct since it is the basis of many calculations - reserve fuel at destination, horsepower, miles per gallon, and prop efficiency. 



Thanks all-

Bill DeRouchey

N939SB





--- On Wed, 1/7/09, RV Builder (Michael Sausen)  <rvbuilder(at)sausen.net> wrote:

 	  Quote: 	
		  From: RV Builder (Michael Sausen) <rvbuilder(at)sausen.net>

Subject: RE: Fuel Flow

To: "rv10-list(at)matronics.com" <rv10-list(at)matronics.com>

Date: Wednesday, January 7, 2009, 6:25 AM



             

Pascal,   

     

  I wouldn¢t worry about it much, lots of people have put it in the stock location.  If the error is really apparent, I would try Matt¢s dampener before trying to relocate it.     

     

Michael   

         

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of pascal

 Sent: Tuesday, January 06, 2009 8:03 PM

 To: rv10-list(at)matronics.com

 Subject: Re: Fuel Flow   

  

  

       

Not sure how I missed that the floscan is in the wrong location the last couple of years..    

    

Dave;   

    

I don¢t see any room to move my floscan from the Van's plans location to near the spider, how did you make it so it all fits?   

    

Thanks!   

    

Pascal   

  

       	  Quote: 	
		  



ronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

matronics.com">http://forums.matronics.com

ronics.com/contribution">http://www.matronics.com/contribution



	


	
 [quote][b]

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Wed Jan 07, 2009 8:06 pm Post subject: Fuel Flow

Bill,



While I do see the increase in fuel flow, just like you do, with

mine installed in the stock location, it doesn't cause me any

headaches.  I only use the fuel boost for maybe 60 seconds

during takeoff, and even on landing if I do, it's only for

about 60 seconds again....just that timeframe that I'm under

about 500' AGL.  If you only use it a couple minutes during

the flight, it won't change those readings much at all. I've

consistently been accurate to within about .1-.2 gallons

over a 40-45 gallon flight, so it's just not worth worrying

about.  In over 400 hours I've never had a fuel fillup that

had any noticeable amount of difference over what the totalizer

told me I should be adding.



If you're going to use it for HP, and things like that, yeah,

you'll get a little mis-reading for those few seconds that

you use it.



Tim Olson - RV-10 N104CD - Flying

do not archive

Bill DeRouchey wrote:

 	  Quote: 	
		   Good comments from everyone. I guess I was asleep last year when this 

 was discussed. I read about Matts air-ball but since the stock tubing is 

 straight before and after the flow sensor I thought it applied to a 

 non-stock configuration.

 

 The only reason I had the electrical fuel pump on in cruise was to test 

 the condition with the autopilot on so I could focus on the abnormality.

 

 It would seem that any modification or relocation of the fuel flow 

 sensor could upset the calibration - so it must be recalibrated after 

 the final configuration is in place. It is very important to me that 

 this value is correct since it is the basis of many calculations - 

 reserve fuel at destination, horsepower, miles per gallon, and prop 

 efficiency.

 

 Thanks all-

 Bill DeRouchey

 N939SB

 

 

 

 

 --- On *Wed, 1/7/09, RV Builder (Michael Sausen) 

 /<rvbuilder(at)sausen.net>/* wrote:

 

     From: RV Builder (Michael Sausen) <rvbuilder(at)sausen.net>

     Subject: RE: Fuel Flow

     To: "rv10-list(at)matronics.com" <rv10-list(at)matronics.com>

     Date: Wednesday, January 7, 2009, 6:25 AM

 

     Pascal,

 

      

 

       I wouldn’t worry about it much, lots of people have put it in the

     stock location.  If the error is really apparent, I would try Matt’s

     dampener before trying to relocate it. 

 

      

 

     Michael

 

      

 

     *From:* owner-rv10-list-server(at)matronics.com

     [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of *pascal

     *Sent:* Tuesday, January 06, 2009 8:03 PM

     *To:* rv10-list(at)matronics.com

     *Subject:* Re: Fuel Flow

 

      

 

     Not sure how I missed that the floscan is in the wrong location the

     last couple of years..

 

     Dave;

 

     I don’t see any room to move my floscan from the Van's plans

     location to near the spider, how did you make it so it all fits?

 

     Thanks!

 

     Pascal

 

     *

 

     ronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

     matronics.com">http://forums.matronics.com

     ronics.com/contribution">http://www.matronics.com/contribution

 

     *

 

 *

 

 

 *

gengrumpy(at)aol.com
Guest

Posted: Wed Jan 07, 2009 8:12 pm Post subject: Fuel Flow

My experience is the same as Tim says.



grumpy

N184JM



I wouldn't worry about it unless you want to leave the thing on all  

the time, and then you'd have other problems to contend with.



do not archive



On Jan 7, 2009, at 10:04 PM, Tim Olson wrote:



 	  Quote: 	
		   



 Bill,



 While I do see the increase in fuel flow, just like you do, with

 mine installed in the stock location, it doesn't cause me any

 headaches.  I only use the fuel boost for maybe 60 seconds

 during takeoff, and even on landing if I do, it's only for

 about 60 seconds again....just that timeframe that I'm under

 about 500' AGL.  If you only use it a couple minutes during

 the flight, it won't change those readings much at all. I've

 consistently been accurate to within about .1-.2 gallons

 over a 40-45 gallon flight, so it's just not worth worrying

 about.  In over 400 hours I've never had a fuel fillup that

 had any noticeable amount of difference over what the totalizer

 told me I should be adding.



 If you're going to use it for HP, and things like that, yeah,

 you'll get a little mis-reading for those few seconds that

 you use it.



 Tim Olson - RV-10 N104CD - Flying

 do not archive

 Bill DeRouchey wrote:

> Good comments from everyone. I guess I was asleep last year when  

> this was discussed. I read about Matts air-ball but since the stock  

> tubing is straight before and after the flow sensor I thought it  

> applied to a non-stock configuration.

> The only reason I had the electrical fuel pump on in cruise was to  

> test the condition with the autopilot on so I could focus on the  

> abnormality.

> It would seem that any modification or relocation of the fuel flow  

> sensor could upset the calibration - so it must be recalibrated  

> after the final configuration is in place. It is very important to  

> me that this value is correct since it is the basis of many  

> calculations - reserve fuel at destination, horsepower, miles per  

> gallon, and prop efficiency.

> Thanks all-

> Bill DeRouchey

> N939SB

> --- On *Wed, 1/7/09, RV Builder (Michael Sausen) /<rvbuilder(at)sausen.net 

> >/* wrote:

>    From: RV Builder (Michael Sausen) <rvbuilder(at)sausen.net>

>    Subject: RE: Fuel Flow

>    To: "rv10-list(at)matronics.com" <rv10-list(at)matronics.com>

>    Date: Wednesday, January 7, 2009, 6:25 AM

>    Pascal,

>           I wouldn’t worry about it much, lots of people have put  

> it in the

>    stock location.  If the error is really apparent, I would try  

> Matt’s

>    dampener before trying to relocate it.          Michael

>         *From:* owner-rv10-list-server(at)matronics.com

>    [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of  

> *pascal

>    *Sent:* Tuesday, January 06, 2009 8:03 PM

>    *To:* rv10-list(at)matronics.com

>    *Subject:* Re: Fuel Flow

>         Not sure how I missed that the floscan is in the wrong  

> location the

>    last couple of years..

>    Dave;

>    I don’t see any room to move my floscan from the Van's plans

>    location to near the spider, how did you make it so it all fits?

>    Thanks!

>    Pascal

>    *

>    ronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

>    matronics.com">http://forums.matronics.com

>    ronics.com/contribution">http://www.matronics.com/contribution

>    *

> *

> *

billderou(at)yahoo.com
Guest

Posted: Thu Jan 08, 2009 10:12 am Post subject: Fuel Flow

That was also my conclusion. I only keep it on for departure and arrivals. Although, on Monday I was at 16,500 over the Rockies with 13,000 ft peaks all around and liked the idea of keeping the electric pump on. But these times are rare.



After thinking about the issue overnight I am not going to make any changes. Not worth it and during moderate to severe turbulence the air ball could be filled with fuel rendering it worthless. Its just comforting that others have seen this abnormalilty and I do not need to dig deeper into my aircraft looking and worrying about a fuel leak.



Thanks for the comments,

Bill

 



--- On Wed, 1/7/09, Miller John <gengrumpy(at)aol.com> wrote:

 	  Quote: 	
		  From: Miller John  <gengrumpy(at)aol.com>

Subject: Re: Fuel Flow

To: rv10-list(at)matronics.com

Date: Wednesday, January 7, 2009, 8:10 PM



 	  Quote: 	
		  --> RV10-List message posted by: Miller John <gengrumpy(at)aol.com>My experience is the same as Tim says.grumpyN184JMI wouldn't worry about it unless you want to leave the thing on all thetime, and then you'd have other problems to contend with.do not archiveOn Jan 7, 2009, at 10:04 PM, Tim Olson wrote:> --> RV10-List message posted by: Tim Olson <Tim(at)myrv10.com>> > Bill,> > While I do see the increase in fuel flow, just like you do, with> mine installed in the stock location, it doesn't cause me any> headaches.  I only use the fuel boost for maybe 60 seconds> during takeoff, and even on landing if I do, it's only for> about 60 seconds again....just that timeframe that I'm

 under> about 500' AGL.  If you only use it a couple minutes during> the flight, it won't change those readings much at all. I've> consistently been accurate to within about .1-.2 gallons> over a 40-45 gallon flight, so it's just not worth worrying> about.  In over 400 hours I've never had a fuel fillup that> had any noticeable amount of difference over what the totalizer> told me I should be adding.> > If you're going to use it for HP, and things like that, yeah,> you'll get a little mis-reading for those few seconds that> you use it.> > Tim Olson - RV-10 N104CD - Flying> do not archive> > > Bill DeRouchey wrote:>> Good comments from everyone. I guess I was asleep last year when thiswas discussed. I read about Matts air-ball but since the stock tubing isstraight before and after the flow sensor I thought it applied to

 a non-stockconfiguration.>> The only reason I had the electrical fuel pump on in cruise was totest the condition with the autopilot on so I could focus on the abnormality.>> It would seem that any modification or relocation of the fuel flowsensor could upset the calibration - so it must be recalibrated after the finalconfiguration is in place. It is very important to me that this value is correctsince it is the basis of many calculations - reserve fuel at destination,horsepower, miles per gallon, and prop efficiency.>> Thanks all->> Bill DeRouchey>> N939SB>> --- On *Wed, 1/7/09, RV Builder (Michael Sausen)/<rvbuilder(at)sausen.net>/* wrote:>>    From: RV Builder (Michael Sausen) <rvbuilder(at)sausen.net>>>    Subject: RE: Fuel Flow>>    To: "rv10-list(at)matronics.com"<rv10-list(at)matronics.com>>>    Date:

 Wednesday, January 7, 2009, 6:25 AM>>    Pascal,>>           I wouldn¢t worry about it much, lots of people have put itin the>>    stock location.  If the error is really apparent, I would tryMatt¢s>>    dampener before trying to relocate it.          Michael>>         *From:* owner-rv10-list-server(at)matronics.com>>    [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of *pascal>>    *Sent:* Tuesday, January 06, 2009 8:03 PM>>    *To:* rv10-list(at)matronics.com>>    *Subject:* Re: RV10-List: Fuel Flow>>         Not sure how I missed that the floscan is in the wronglocation the>>    last couple of years..>>    Dave;>>    I don¢t see any room to move my floscan from the Van's plans>>    location to near the spider, how did you make it so it all fits?>>    Thanks!>>   

 Pascal>>    *>>   ronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List>>    matronics.com">http://forums.matronics.com>>   ronics.com/contribution">http://www.matronics.com/contribution>>    *>> * 	
	
 [quote][b]

pascal(at)rv10builder.net
Guest

Posted: Thu Jan 08, 2009 10:58 am Post subject: Fuel Flow

Bill;

 Thanks for bringing this up, I was quite concerned with this  as well, especially when I saw what it would take to rectify it, seeing the  responses from reliable sources certainly put this concern to rest, but glad to  have had it discussed.

  

 Pascal

  



  From: Bill DeRouchey (billderou(at)yahoo.com) 

 Sent: Thursday, January 08, 2009 10:10 AM

 To: rv10-list(at)matronics.com (rv10-list(at)matronics.com) 

 Subject: Re: Fuel Flow

 



            That was also my conclusion. I only keep it on for        departure and arrivals. Although, on Monday I was at 16,500 over the        Rockies with 13,000 ft peaks all around and liked the idea of keeping the        electric pump on. But these times are rare.



After thinking about        the issue overnight I am not going to make any changes. Not worth it and        during moderate to severe turbulence the air ball could be filled with        fuel rendering it worthless. Its just comforting that others have seen        this abnormalilty and I do not need to dig deeper into my aircraft looking        and worrying about a fuel leak.



Thanks for the        comments,

Bill

 



--- On Wed, 1/7/09, Miller John        <gengrumpy(at)aol.com> wrote:

        	  Quote: 	
		  From:          Miller John <gengrumpy(at)aol.com>

Subject: Re: Fuel          Flow

To: rv10-list(at)matronics.com

Date: Wednesday, January 7, 2009,          8:10 PM



 	  Quote: 	
		  --> RV10-List message posted by: Miller John <gengrumpy(at)aol.com>My experience is the same as Tim says.grumpyN184JMI wouldn't worry about it unless you want to leave the thing on all thetime, and then you'd have other problems to contend with.do not archiveOn Jan 7, 2009, at 10:04 PM, Tim Olson wrote:> --> RV10-List message posted by: Tim Olson <Tim(at)myrv10.com>> > Bill,> > While I do see the increase in fuel flow, just like you do, with> mine installed in the stock location, it doesn't cause me any> headaches.  I only use the fuel boost for maybe 60 seconds> during takeoff, and even on landing if I do, it's only for> about 60 seconds again....just that timeframe that I'm

 under> about 500' AGL.  If you only use it a couple minutes during> the flight, it won't change those readings much at all. I've> consistently been accurate to within about .1-.2 gallons> over a 40-45 gallon flight, so it's just not worth worrying> about.  In over 400 hours I've never had a fuel fillup that> had any noticeable amount of difference over what the totalizer> told me I should be adding.> > If you're going to use it for HP, and things like that, yeah,> you'll get a little mis-reading for those few seconds that> you use it.> > Tim Olson - RV-10 N104CD - Flying> do not archive> > > Bill DeRouchey wrote:>> Good comments from everyone. I guess I was asleep last year when thiswas discussed. I read about Matts air-ball but since the stock tubing isstraight before and after the flow sensor I thought it applied to

 a non-stockconfiguration.>> The only reason I had the electrical fuel pump on in cruise was totest the condition with the autopilot on so I could focus on the abnormality.>> It would seem that any modification or relocation of the fuel flowsensor could upset the calibration - so it must be recalibrated after the finalconfiguration is in place. It is very important to me that this value is correctsince it is the basis of many calculations - reserve fuel at destination,horsepower, miles per gallon, and prop efficiency.>> Thanks all->> Bill DeRouchey>> N939SB>> --- On *Wed, 1/7/09, RV Builder (Michael Sausen)/<rvbuilder(at)sausen.net>/* wrote:>>    From: RV Builder (Michael Sausen) <rvbuilder(at)sausen.net>>>    Subject: RE: Fuel Flow>>    To: "rv10-list(at)matronics.com"<rv10-list(at)matronics.com>>>    Date:

 Wednesday, January 7, 2009, 6:25 AM>>    Pascal,>>           I wouldn¢t worry about it much, lots of people have put itin the>>    stock location.  If the error is really apparent, I would tryMatt¢s>>    dampener before trying to relocate it.          Michael>>         *From:* owner-rv10-list-server(at)matronics.com>>    [mailto:owner-rv10-list-server(at)matronics.com] *On Behalf Of *pascal>>    *Sent:* Tuesday, January 06, 2009 8:03 PM>>    *To:* rv10-list(at)matronics.com>>    *Subject:* Re: Fuel Flow>>         Not sure how I missed that the floscan is in the wronglocation the>>    last couple of years..>>    Dave;>>    I don¢t see any room to move my floscan from the Van's plans>>    location to near the spider, how did you make it so it all fits?>>    Thanks!>>   

 Pascal>>    *>>   ronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List>>    matronics.com">http://forums.matronics.com>>   ronics.com/contribution">http://www.matronics.com/contribution>>    *>> * 	
	
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