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Lycoming O-360 Fuel Flow Rate

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Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Fri Dec 18, 2015 2:40 pm Post subject: Lycoming O-360 Fuel Flow Rate

I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt



-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Fri Dec 18, 2015 2:40 pm Post subject: Lycoming O-360 Fuel Flow Rate

I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt



-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Fri Dec 18, 2015 2:40 pm Post subject: Lycoming O-360 Fuel Flow Rate

I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt



-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Fri Dec 18, 2015 2:43 pm Post subject: Lycoming O-360 Fuel Flow Rate

I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt



-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Sat Dec 19, 2015 12:47 pm Post subject: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  



Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.



The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 



Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?



Thanks again for the great feedback!



Matt Dralle



At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:



 	  Quote: 	
		  I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt


	


-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Sat Dec 19, 2015 12:47 pm Post subject: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  



Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.



The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 



Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?



Thanks again for the great feedback!



Matt Dralle



At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:



 	  Quote: 	
		  I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt


	


-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Sat Dec 19, 2015 12:48 pm Post subject: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  



Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.



The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 



Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?



Thanks again for the great feedback!



Matt Dralle



At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:



 	  Quote: 	
		  I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt


	


-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Sat Dec 19, 2015 12:50 pm Post subject: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  



Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.



The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 



Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?



Thanks again for the great feedback!



Matt Dralle



At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:



 	  Quote: 	
		  I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  



I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?



Thanks for the feedback,



Matt


	


-

Matt Dralle



RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!



RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!



Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.  http://klvk.matronics.com

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Tue Dec 22, 2015 12:19 pm Post subject: Lycoming O-360 Fuel Flow Rate

Well, it was probably the fuel pump.  I think my flow rates right after replacing the fuel pump (but before I replaced the carb) were probably alright as they were similar to what I saw after the new carb.  But, it was time for a new carb anyway, so I guess it worked out.  Btw, as if all of this debacle wasn't frustrating enough, last weekend while trying to test all of this, the battery went dead.  Checking the logs it was 36 months ago since I replaced it the last time.  Guess that's about right.  Sigh.  Is it time to fly it yet?  I've been working on it enough lately.  

Matt Dralle

RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!

RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!

Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.

At 10:24 AM 12/21/2015 Monday, you wrote:

 	  Quote: 	
		  So what did you do to fix the problem Matt?

Harry Crosby

----------

From: "Matt Dralle" <dralle(at)matronics.com>

To: "RV-List" <rv-list(at)matronics.com>, LycomingEngines-list(at)matronics.com, rv6-list(at)matronics.com, rv10-list(at)matronics.com

Sent: Saturday, December 19, 2015 12:44:41 PM

Subject: RV-List: Re: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  

Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.

The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 

Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?

Thanks again for the great feedback!

Matt Dralle

At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:

>I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  

>

>I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?

>

>Thanks for the feedback,

>

>Matt

-

Matt Dralle

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Tue Dec 22, 2015 12:20 pm Post subject: Lycoming O-360 Fuel Flow Rate

Well, it was probably the fuel pump.  I think my flow rates right after replacing the fuel pump (but before I replaced the carb) were probably alright as they were similar to what I saw after the new carb.  But, it was time for a new carb anyway, so I guess it worked out.  Btw, as if all of this debacle wasn't frustrating enough, last weekend while trying to test all of this, the battery went dead.  Checking the logs it was 36 months ago since I replaced it the last time.  Guess that's about right.  Sigh.  Is it time to fly it yet?  I've been working on it enough lately.  

Matt Dralle

RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!

RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!

Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.

At 10:24 AM 12/21/2015 Monday, you wrote:

 	  Quote: 	
		  So what did you do to fix the problem Matt?

Harry Crosby

----------

From: "Matt Dralle" <dralle(at)matronics.com>

To: "RV-List" <rv-list(at)matronics.com>, LycomingEngines-list(at)matronics.com, rv6-list(at)matronics.com, rv10-list(at)matronics.com

Sent: Saturday, December 19, 2015 12:44:41 PM

Subject: RV-List: Re: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  

Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.

The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 

Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?

Thanks again for the great feedback!

Matt Dralle

At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:

>I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  

>

>I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?

>

>Thanks for the feedback,

>

>Matt

-

Matt Dralle

_________________
Matt Dralle
Matronics Email List Administrator

Matt Dralle
Site Admin

Joined: 08 Nov 2005
Posts: 25203
Location: Livermore CA USA

Posted: Tue Dec 22, 2015 12:20 pm Post subject: Lycoming O-360 Fuel Flow Rate

Well, it was probably the fuel pump.  I think my flow rates right after replacing the fuel pump (but before I replaced the carb) were probably alright as they were similar to what I saw after the new carb.  But, it was time for a new carb anyway, so I guess it worked out.  Btw, as if all of this debacle wasn't frustrating enough, last weekend while trying to test all of this, the battery went dead.  Checking the logs it was 36 months ago since I replaced it the last time.  Guess that's about right.  Sigh.  Is it time to fly it yet?  I've been working on it enough lately.  

Matt Dralle

RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!

RV-6 #20916 N360EM "The Flyer"

http://www.mattsrv6.com - Matt's RV-6 Revitalization Log

Status: 300+ Hours - Full Flyer Mode!

Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.

At 10:24 AM 12/21/2015 Monday, you wrote:

 	  Quote: 	
		  So what did you do to fix the problem Matt?

Harry Crosby

----------

From: "Matt Dralle" <dralle(at)matronics.com>

To: "RV-List" <rv-list(at)matronics.com>, LycomingEngines-list(at)matronics.com, rv6-list(at)matronics.com, rv10-list(at)matronics.com

Sent: Saturday, December 19, 2015 12:44:41 PM

Subject: Re: Lycoming O-360 Fuel Flow Rate

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  

Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.

The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 

Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?

Thanks again for the great feedback!

Matt Dralle

At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:

>I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  

>

>I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?

>

>Thanks for the feedback,

>

>Matt

-

Matt Dralle

_________________
Matt Dralle
Matronics Email List Administrator

jay.pearlman(at)yahoo.com
Guest

Posted: Tue Dec 22, 2015 9:57 pm Post subject: Lycoming O-360 Fuel Flow Rate

Matt,

Thanks for sharing with us. Each of us has our own story. Mine was to learn that the engine mount supplied with my Van's RV6 kit did not match with the engine sold to me by Vans for the RV6. It was another lesson of "don't assume". After flying for some hours, I noticed rubbing and from a forum someone said they had the same problem and the choices were a new engine, a new mount or live with it. The only viable option for safety and my pocket book was a new mount which had to be custom made ($1200). Ouch. Otherwise I would have had to rebuild the entire front end. Everyone was helpful and I am installing the mount now. I should know in about three weeks if the solution has been found.

More to follow.

       From: Matt Dralle <dralle(at)matronics.com>

 To: rv-list(at)matronics.com; LycomingEngines-list(at)matronics.com; rv6-list(at)matronics.com; rv10-list(at)matronics.com 

 Sent: Tuesday, December 22, 2015 12:18 PM

 Subject: Re: Lycoming O-360 Fuel Flow Rate 

--> RV6-List message posted by: Matt Dralle <dralle(at)matronics.com (dralle(at)matronics.com)>

Well, it was probably the fuel pump.  I think my flow rates right after replacing the fuel pump (but before I replaced the carb) were probably alright as they were similar to what I saw after the new carb.  But, it was time for a new carb anyway, so I guess it worked out.  Btw, as if all of this debacle wasn't frustrating enough, last weekend while trying to test all of this, the battery went dead.  Checking the logs it was 36 months ago since I replaced it the last time.  Guess that's about right.  Sigh.  Is it time to fly it yet?  I've been working on it enough lately.  

Matt Dralle

RV-8 #82880 N998RV "Ruby Vixen"

http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log

http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log

http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel

Status: 210+ Hours TTSN - Version 2.0 Now Flying!

RV-6 #20916 N360EM "The Flyer"

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Status: 300+ Hours - Full Flyer Mode!

Matt's Livermore Airport Live ATC Stream!

Check out the live ATC stream directly from my hangar at the Livermore

Airport.  Includes both Tower and Ground transmissions.  Archives too!

For entertainment purposes only.

At 10:24 AM 12/21/2015 Monday, you wrote:

 	  Quote: 	
		  So what did you do to fix the problem Matt?

Harry Crosby

----------

From: "Matt Dralle" <dralle(at)matronics.com (dralle(at)matronics.com)>

To: "RV-List" <rv-list(at)matronics.com (rv-list(at)matronics.com)>, LycomingEngines-list(at)matronics.com (LycomingEngines-list(at)matronics.com), rv6-list(at)matronics.com (rv6-list(at)matronics.com), rv10-list(at)matronics.com (rv10-list(at)matronics.com)

Sent: Saturday, December 19, 2015 12:44:41 PM

Subject: RV-List: Re: Lycoming O-360 Fuel Flow Rate

--> RV-List message posted by: Matt Dralle <dralle(at)matronics.com (dralle(at)matronics.com)>

Thank you to everyone that responded!!  There were some great comments that got me going down the right path.  

Last night I got the cowling back on and took the RV-6 out on the runway and ran it up to full power with the intent of carefully watching the flow rate and aborting the take off if the flow wasn't sufficiently high enough.  I'm happy to report that the flow rate climbed nicely up though the teens as my takeoff roll progressed.  I lifted off around 15-16 gph and decided to take it around the pattern.  As I climbed through the crosswind to downwind turn I noted that the flow was in the 18.5gph range, RPM was at 2700, and EGTs were low 1300's.  After a few more loops around the pattern everything seemed to be working as expected.  I took it out of the pattern and dialed it into my normal cruse configuration which is typically 75% power at 2250 RPM and leaned to about 1425 on the hottest EGT.  Everything sounded and felt fine.  Flow was right at 9.5 GPH per usual.

The only weird thing I noticed was at about 1700 RPM.  When I turn from Downwind to Base and go from idle to about 2000 RPM like I usually do, right about 1700 RPM the engine kind of sags and then picks back up.  It is very repeatable.  Strangely there is no sag on the ground after a touch and go when I push the throttle in fast going from idle to full power anymore like there was with the old carb. 

Does anyone have any idea what that sag at 1700 is?  Is there a nurd knob on the carb for this specifically?

Thanks again for the great feedback!

Matt Dralle

At 02:38 PM 12/18/2015 Friday, Matt Dralle wrote:

>I'm still chasing down this weird problem with low fuel flow rates on the RV-6.  I've replaced the mechanical fuel pump and got a rebuilt 4-5 carburetor, both of which were well over do for replacement/overhaul anyway.  I haven't put the cowling back on yet, but I did a static run up to about 2350-2400 and am seeing about 9gph, which seems low to me?  

>

>I pulled the fuel line off the carburetor and turned the electric fuel pump on and saw about 21 GPH flow.  Is that considered "normal" or too low?

>

>Thanks for the feedback,

>

>Matt

-

Matt Dralle

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