VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > Main > RV General Discussion/News
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 01-24-2016, 06:44 PM
Guilhermepilot's Avatar
Guilhermepilot Guilhermepilot is offline
 
Join Date: Jan 2013
Location: brazil
Posts: 316
Question Engine quit on stall pratice

Today, I performed some acro, and a stall. After reducing to idle speed and have my speed drained at about 53 kt engine quit, a few seconds later a restared with no issues, so on ground idle is about 700RPM pump on and off does not affect idle. Very weird.
__________________
Guilherme Plassmann (Brazil)
RV7A (Mr Flame) slow kit S/N 74285 Finished 04/14/15😀😀😀😀flying
G3X
Superior IO360
Sterba prop
TSFlightlines hoses
LR30,PRM1,C560,C510S,HS125,B350 FAA/ANAC Pilot

Donation made 2016
Reply With Quote
  #2  
Old 01-24-2016, 07:03 PM
flyboykelly's Avatar
flyboykelly flyboykelly is offline
 
Join Date: Jun 2006
Location: Port Orange, FL (7FL6)
Posts: 312
Default

Have you done any high AOA fuel flow testing on the ground. If not, get the aircraft to a nose high attitude, disconnect the fuel line at the fuel servo, and using your electric fuel pump measure your flow rate. You should be getting at least 150% of the takeoff fuel flow. If not, you may have a restriction in your fuel system at a high AOA. Good luck!
__________________
Flying as of 1-12-2016!!!!!
Reply With Quote
  #3  
Old 01-24-2016, 07:08 PM
Xkuzme1's Avatar
Xkuzme1 Xkuzme1 is offline
 
Join Date: Jan 2015
Location: KC, MO
Posts: 381
Default

Did you have the fuel pump on during your acro and stall series? Carb heat out?

Low idle could make fuel pressure drop if certain engine parts are excessively worn.

Carb heat can make you lose 50-75 rpms.

When I finish my runups, the last thing I do is put the carb heat on, and pull the throttle back abruptly and make sure it continues to idle.

Where was the fuel level? Were you on the low wing (fuel)? If so, did that wing drop after the stall?

Hope you figure it out soon! That's where I'd start.

X
__________________
RV-4 - 0-320 (160HP)
www.KCFlight.org
Tinker
ATP/CFI/II/MEI
N617TN
Reply With Quote
  #4  
Old 01-24-2016, 07:12 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 6,314
Default

I am not implying a recommendation here, but was the boost pump on? (I am assuming it was not) And, have you checked the idle condition on the ground to see if the mixture is proper?

Thoughts for above - is the mechanical pump dropping pressure (and thus flow) at high suction conditions (pitch angle/AOA)? And if the pressure dropped a little, but not enough to set off your alarm, the idle fuel rate could have dropped and leaned the mixture. In the latter case, a mixture adjustment would help.

Just some thoughts.
__________________
Bill

RV-7
Reply With Quote
  #5  
Old 01-24-2016, 09:01 PM
N941WR's Avatar
N941WR N941WR is offline
 
Join Date: Jan 2005
Location: SC
Posts: 12,887
Default

I had a similar issue and eventually traced it down to a section of aluminum fuel line that went between my gascolator and the fuel flow meter. Once I insulated the fuel line, the problem went away.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
Reply With Quote
  #6  
Old 01-24-2016, 09:20 PM
crabandy crabandy is offline
 
Join Date: Jan 2010
Location: Ottawa, Ks
Posts: 2,309
Default

Lightweight props also play a role. Mine idles at 480-500 but I have electronic ignition and associated timing changes, engine runs fine during stalls but quits during hammerheads.
__________________
RV 7 500 hours and counting
20 donation done
Reply With Quote
  #7  
Old 01-24-2016, 09:30 PM
NYTOM NYTOM is offline
 
Join Date: Jun 2005
Location: Raleigh, North Carolina
Posts: 1,187
Default

This may seem oversimplified but are you sure you had applied carb heat?
I had a plane years ago that would freeze over incredibly fast without carb heat under the right conditions after idling down in a glide.
__________________
Tom Norwood
Classic "Short Tail 6A N822PM
TMX-O360 FP
Reply With Quote
  #8  
Old 01-25-2016, 07:02 AM
Guilhermepilot's Avatar
Guilhermepilot Guilhermepilot is offline
 
Join Date: Jan 2013
Location: brazil
Posts: 316
Default

Guys, mine is FI and boost pump was on, i will consider all advises to solve the problem, as a matter o fact my sterba prop is very lightweight. many thanks
__________________
Guilherme Plassmann (Brazil)
RV7A (Mr Flame) slow kit S/N 74285 Finished 04/14/15😀😀😀😀flying
G3X
Superior IO360
Sterba prop
TSFlightlines hoses
LR30,PRM1,C560,C510S,HS125,B350 FAA/ANAC Pilot

Donation made 2016
Reply With Quote
  #9  
Old 01-25-2016, 07:36 AM
Low Pass's Avatar
Low Pass Low Pass is offline
 
Join Date: May 2006
Location: Houston
Posts: 2,121
Default

Quote:
Originally Posted by Guilhermepilot View Post
Guys, mine is FI and boost pump was on, i will consider all advises to solve the problem, as a matter o fact my sterba prop is very lightweight. many thanks
Try it without the boost pump. I personally don't use boost during flight unless I have a loss of fuel pressure.

Otherwise, just remember, when you notice the prop *not* spinning, put the nose down. You must be stalled!
__________________
Bryan

Houston
Reply With Quote
  #10  
Old 01-25-2016, 09:43 AM
AlexPeterson's Avatar
AlexPeterson AlexPeterson is offline
 
Join Date: Sep 2005
Location: Ottertail, MN
Posts: 2,458
Default

What was outside temperature? If warm, it is probably just fuel boiling in the injector lines (or anywhere downstream of the servo), causing some intermittency in fuel delivery. With the low fuel flow rates for idle, low cooling air rate, combined with a lightweight prop, it is not too surprising it quit.
__________________
Alex Peterson
RV6A N66AP 1750+ hours
KADC, Wadena, MN
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 12:26 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.