Matronics Email Lists Forum Index Matronics Email Lists
BBS Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

fuel flow at takeoff power

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> RV10-List
View previous topic :: View next topic  
Author Message
dlm34077



Joined: 10 Feb 2007
Posts: 115
Location: AZ

PostPosted: Thu Feb 16, 2017 4:29 am    Post subject: fuel flow at takeoff power Reply with quote

I have been adjusting the mixture control cable attempting to make the control hit both the full rich stop and the idle cutoff stop. It appears that the cable (AS custom with Teflon cores) is about .050 inch shorter in the throw than expected. The result is that the adjustment is close but not exact. Although I can adjust the rich stop within .030 and the idle cut off stop within .010, I still wonder whether fuel flow is sufficient for takeoff power. Current fuel flow gauge says about 24 +- .5 gph and idle cutoff requires that the control be fully aft. Anyone have any numbers that they use to confirm proper fuel flow for takeoff. The IO540 book seems to say that 24-25 gph is correct. I am now determining whether to re make the hole in the mixture control arm or order a new cable ($200); the cable cost is not the problem but the labor (lots?) necessary to re install another cable. I have also been told by Precision Air Motive (PAM) that sufficient fuel flow is certain when leaning to peak at full power shows at least 100f rich of peak is obtained. Any comments or suggestions?

David McNeill

This email has been checked for viruses by Avast antivirus software.
www.avast.com


- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?RV10-List
Back to top
View user's profile Send private message Send e-mail
Lenny Iszak



Joined: 23 Mar 2008
Posts: 215

PostPosted: Thu Feb 16, 2017 4:55 am    Post subject: Re: fuel flow at takeoff power Reply with quote

I had the same issue with the new cables. Another good reminder for anyone upgrading their control cables, get them with a 1/8" longer throw.
You could check engine monitor data and compare takeoff EGTs before and after the control cable swap.
I ended up playing with the adjustments until i got to a compromise similar to yours. EGTs and fuel flows are the same as before.

I wouldn't be leaning anywhere close to peak EGT at full power though.


- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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

_________________
Lenny Iszak
Palm City, FL
2014 RV-10, N311LZ - 280 hrs
Back to top
View user's profile Send private message
jesse(at)saintaviation.co
Guest





PostPosted: Thu Feb 16, 2017 5:20 am    Post subject: fuel flow at takeoff power Reply with quote

That fuel flow sounds to be on the low side of normal. If you can get to he full rich stop and lean enough to get the engine to quit at idle, that is where I would leave it.

Jesse Saint
Saint Aviation, Inc.
352-427-0285
jesse(at)saintaviation.com (jesse(at)saintaviation.com)
Sent from my iPad

On Feb 16, 2017, at 7:28 AM, David <dlm34077(at)cox.net (dlm34077(at)cox.net)> wrote:
Quote:


I have been adjusting the mixture control cable attempting to make the control hit both the full rich stop and the idle cutoff stop. It appears that the cable (AS custom with Teflon cores) is about .050 inch shorter in the throw than expected. The result is that the adjustment is close but not exact. Although I can adjust the rich stop within .030 and the idle cut off stop within .010, I still wonder whether fuel flow is sufficient for takeoff power. Current fuel flow gauge says about 24 +- .5 gph and idle cutoff requires that the control be fully aft. Anyone have any numbers that they use to confirm proper fuel flow for takeoff. The IO540 book seems to say that 24-25 gph is correct. I am now determining whether to re make the hole in the mixture control arm or order a new cable ($200); the cable cost is not the problem but the labor (lots?) necessary to re install another cable. I have also been told by Precision Air Motive (PAM) that sufficient fuel flow is certain when leaning to peak at full power shows at least 100f rich of peak is obtained. Any comments or suggestions?

David McNeill



This email has been checked for viruses by Avast antivirus software.
www.avast.com



- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?RV10-List
Back to top
bill.peyton



Joined: 19 Sep 2010
Posts: 175
Location: St. Louis, MO

PostPosted: Thu Feb 16, 2017 5:26 am    Post subject: Re: fuel flow at takeoff power Reply with quote

24-25 is what I see

- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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

_________________
Bill
WA0SYV
Aviation Partners, LLC
Back to top
View user's profile Send private message
Kelly McMullen



Joined: 16 Apr 2008
Posts: 1048
Location: Sun Lakes AZ

PostPosted: Thu Feb 16, 2017 6:18 am    Post subject: fuel flow at takeoff power Reply with quote

Remember that your field elevation is almost 1400 ft and your density altitude is normally above 2000 ft. Fuel flow will decrease with altitude, because you cannot get to 29" of MP. I see about 22.7 to maybe 23 gph, and would like to have 24"

What is your EGT on hottest couple cylinders right after liftoff? If below 1300 you have nothing to worry about.

I got my cables from McFarlane ($$$) that are a little long, and have no problem getting full mixture travel.

-sent from the I-droid implanted in my forearm

On Thu, Feb 16, 2017 at 5:28 AM, David <dlm34077(at)cox.net (dlm34077(at)cox.net)> wrote:
Quote:

 
I have been adjusting the mixture control cable attempting to make the control hit both the full rich stop and the idle cutoff stop. It appears that the cable (AS custom with Teflon cores) is about .050 inch shorter in the throw than expected. The result is that the adjustment is close but not exact. Although I can adjust the rich stop within .030 and the idle cut off stop within .010, I still wonder whether fuel flow is sufficient for takeoff power. Current fuel flow gauge says about 24 +- .5 gph and idle cutoff requires that the control be fully aft. Anyone have any numbers that they use to confirm proper fuel flow for takeoff. The IO540 book seems to say that 24-25 gph is correct. I am now determining whether to re make the hole in the mixture control arm or order a new cable ($200); the cable cost is not the problem but the labor (lots?) necessary to re install another cable. I have also been told by Precision Air Motive (PAM) that sufficient fuel flow is certain when leaning to peak at full power shows at least 100f rich of peak is obtained. Any comments or suggestions?
 
David McNeill



This email has been checked for viruses by Avast antivirus software.
www.avast.com



- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor
KCHD
Back to top
View user's profile Send private message
Bob Turner



Joined: 03 Jan 2009
Posts: 768
Location: Castro Valley, CA

PostPosted: Thu Feb 16, 2017 10:05 am    Post subject: Re: fuel flow at takeoff power Reply with quote

Are undrilled mixture control arms available? That might be the easiest solution. You might also look at re-clocking that arm. If the arm is currently perpendicular to the cable at mid-setting, that will take the most control throw to get the desired rotation. If you remove the arm, rotate it, re-install, you may make up the small length you need to go stop to stop. Of course don't go over-center.

- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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

_________________
Bob Turner
RV-10 QB
Back to top
View user's profile Send private message Send e-mail
Tim Olson



Joined: 25 Jan 2007
Posts: 2647

PostPosted: Fri Feb 17, 2017 7:19 am    Post subject: fuel flow at takeoff power Reply with quote

Like Lenny recommended, when you order cables I'd ask for
an additional bit of throw. I had the same thing happen on
my RV-14. Now, the one thing you can't afford is to not get
full fuel delivery when needed, so I'd err on the side of
hitting the full-rich stop, then see if going full lean
always definitely kills the engine. If so, you should be good,
but, what I did on mine is drill the arm and make sure I could
hit both stops. On my RV-14 it isn't quite as pretty as my
RV-10. On the -10, things are drilled so well that most
controls go stop to stop and are almost exactly at the
end of the slots on the quadrant. On the RV-14, the throw
of the cables wasn't enough, so I have at least one that
stops about 1/2" from the end of the slot when you pull it
all the way back. But, they all go stop to stop on the
far end. I did have to drill holes in arms to get it that
way. Don't forget, you can also drill higher or lower
holes in the quadrant levers where the clevis attaches.
Tim

On 2/16/2017 6:28 AM, David wrote:
Quote:


I have been adjusting the mixture control cable attempting to make the
control hit both the full rich stop and the idle cutoff stop. It appears
that the cable (AS custom with Teflon cores) is about .050 inch shorter
in the throw than expected. The result is that the adjustment is close
but not exact. Although I can adjust the rich stop within .030 and the
idle cut off stop within .010, I still wonder whether fuel flow is
sufficient for takeoff power. Current fuel flow gauge says about 24 +-
.5 gph and idle cutoff requires that the control be fully aft. Anyone
have any numbers that they use to confirm proper fuel flow for takeoff.
The IO540 book seems to say that 24-25 gph is correct. I am now
determining whether to re make the hole in the mixture control arm or
order a new cable ($200); the cable cost is not the problem but the
labor (lots?) necessary to re install another cable. I have also been
told by Precision Air Motive (PAM) that sufficient fuel flow is certain
when leaning to peak at full power shows at least 100f rich of peak is
obtained. Any comments or suggestions?

David McNeill

------------------------------------------------------------------------
Avast logo <https://www.avast.com/antivirus>

This email has been checked for viruses by Avast antivirus software.
www.avast.com <https://www.avast.com/antivirus>


- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?RV10-List
Back to top
View user's profile Send private message Send e-mail
rv10flyer



Joined: 25 Aug 2009
Posts: 364

PostPosted: Tue Feb 21, 2017 9:55 pm    Post subject: Re: fuel flow at takeoff power Reply with quote

I am seeing 25-25.5 gph and 1240-1250 EGT's on takeoff from 663' elev.

- The Matronics RV10-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

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

_________________
Wayne G.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> RV10-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group