SUPPORT OUR SPONSOR

Go Back   Club Cobra > Club Cobra Tech Areas > Shop Talk

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

Keith Craft Racing
Nevada Classics
MMG Superformance
Main Menu
Nevada Classics
Nevada Classics
MMG Superformance
MMG Superformance
Advertise at CC
Banner Ad Rates
Keith Craft Racing
MMG Superformance
MMG Superformance
MMG Superformance
April 2024
S M T W T F S
  1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30        

Kirkham Motorsports

Reply
 
LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 09-13-2002, 03:51 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2001
Location: Washington DC Metro (Virginia), VA
Cobra Make, Engine: Classic Roadsters, Tweaked 351W, T-5Z, CRII Tech Support Team.
Posts: 1,895
Not Ranked     
Default Engine stall on hard braking cure?

Hard braking causes engine to stall.

Have experienced this on other Holley equipped cars before, but very fast decelleration on Cobra makes it worse. Hit the brakes good and hard and motor stalls.

I know Summit/Holley have primary jet extenders so fuel gets picked up on foreward slosh fuel during braking.

What works to fix this?
Reply With Quote
  #2 (permalink)  
Old 09-13-2002, 03:58 PM
mikiec's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jun 2000
Location: Gilford, NH
Cobra Make, Engine: FFR 302 carb
Posts: 8,121
Not Ranked     
Default

Actually what Holley suggests are some secondary vent whistles.

The cause is fuel spilling over from secondary fuel bowls.

Plastic pieces that fit in the secondary fuel bowl. Also, lowering your fuel level can help some.

Been there done that.

mike
__________________
All gave some; Some gave all. Rest in peace my brothers.

http://s210.photobucket.com/albums/bb222/mikiec66/
Reply With Quote
  #3 (permalink)  
Old 09-13-2002, 04:02 PM
392cobra's Avatar
6th Generation Texan
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Devil's Backbone,RR 32, TX
Cobra Make, Engine: Lone Star Classics #240,Candy Apple Red,Keith Craft 418w - 602 HP,584 TQ
Posts: 8,157
Not Ranked     
Default vent baffle ?

if you put extenders on the primary you will have a fuel starvation problem on acceleration.
i take it you have a vent baffle (whistle) on the secondaries,if not that is needed.fuel level set where it just trickels out.
off road holleys have the primary & secondary vents tied together
with a tube.forms an arc,with the vent opening at the top.
Reply With Quote
  #4 (permalink)  
Old 09-13-2002, 04:07 PM
Pete C's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Nov 2001
Location: Davis, Ca
Cobra Make, Engine: ERA 427 SC #004 (Original ERA?)
Posts: 561
Not Ranked     
Default Stall on braking

I had the same problem and the vent whistles cured it! This is particularly problematic with the dual quad set up as the carbs are on backward!

Good luck, Pete
__________________
Drive it like you stole it!
Reply With Quote
  #5 (permalink)  
Old 09-14-2002, 11:40 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2001
Location: Washington DC Metro (Virginia), VA
Cobra Make, Engine: Classic Roadsters, Tweaked 351W, T-5Z, CRII Tech Support Team.
Posts: 1,895
Not Ranked     
Default

Carb is reasonably new 700 DP, and came with vent whistles already installed. Floats are set to where fuel just dribbles out. Only happens on hard braking. Engine restarts right away, but still potentially dangerous driving condition.

Will try connecting vents with a tube. Any other suggestions?
Reply With Quote
  #6 (permalink)  
Old 09-15-2002, 10:58 AM
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2000
Location: Menasha, WI
Cobra Make, Engine: B+B 351w #112
Posts: 600
Not Ranked     
Default

Try spark plug boots on the vents. Seen this done before. Cheap way to check if thats it. Jim
Reply With Quote
  #7 (permalink)  
Old 09-15-2002, 11:21 AM
mikiec's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jun 2000
Location: Gilford, NH
Cobra Make, Engine: FFR 302 carb
Posts: 8,121
Not Ranked     
Default

To check if it is a vent issue try to connect both vents with a piece of tubing. If this stops the stalling then try a longer vent whistle. If it does not then your throttle plates are closing off completely. causing a very lean condition. Holley has a dashpot that keeps the throttle plates from closing down quickly.

http://www.holley.com/HiOctn/ProdLin...MSCA/11-4.html

Or try setting your idle speed a little higher.

Mike
__________________
All gave some; Some gave all. Rest in peace my brothers.

http://s210.photobucket.com/albums/bb222/mikiec66/
Reply With Quote
  #8 (permalink)  
Old 09-15-2002, 07:23 PM
SCOBRAC's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2002
Location: Northern California, CA
Cobra Make, Engine: -Sold- Contemporary 427S/C # CCX-3152 1966 427 Med Rise Side Oiler, 8v 3.54:1 Salisbury IRS, Koni's.. (Now I'm riding Harleys)
Posts: 2,567
Not Ranked     
Default

a small piece of rubber hose extending the vent whistle by about 2" works most of the time.. not real sexy but you only see it when you have the air cleaners off..
__________________
michael

A man that is young in years, may be old in hours, if he have lost no time. But that happeneth rarely. Generally, youth is like the first cogitations, not so wise as the second. For there is a youth in thoughts, as well as in ages... Sir Francis Bacon (1561-1626)
Reply With Quote
  #9 (permalink)  
Old 09-16-2002, 07:49 AM
Mr.Fixit's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2002
Location: so cal, Cal
Cobra Make, Engine: I used to fix them for a living
Posts: 2,563
Not Ranked     
Default

Rubber connector hose as stated , plus the white vent baffles that are about 2" long made by holley.
__________________
In a fit of 16 year old genius, I looked down through the carb while cranking it to see if fuel was flowing, and it was. Flowing straight up in a vapor cloud, around my head, on fire.
Reply With Quote
  #10 (permalink)  
Old 09-17-2002, 04:31 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,439
Not Ranked     
Question Bought a vent whistle - now what?

The timing of this thread was perfect for solving my engine stall problem. I managed to track down and buy a vent whistle with miniature rivet. But it didn't come with instructions. Before I disassemble my carb, I'd like to have some idea of where the vent whistle goes and how it installs. Can anyone provide instructions or directions to a source of installation instructions? Thanks.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #11 (permalink)  
Old 09-17-2002, 07:20 AM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2001
Posts: 32
Not Ranked     
Default

Tommy,
The vent whistle is installed in the vent hole in the metering block of the carb.
1.) Remove the fuel bowl and metering block.
2.) Insert the vent whistle into the vent hole on the side toward the fuel bowl.
3.) Drill an appropriately sized hole for the drive rivet through the top of the metering block and the vent whistle. (Can't remember the recommended number size drill for this - anybody else know?)
4.) Tap the drive rivet into the drilled hole, securing the vent whistle in place.
5.) CLEAN ANY DRILL DEBRIS FROM THE METERING BLOCK! Reassemble the carb with new gaskets.

I believe Holley still sells what they call a "Trick Kit" that included a full rebuild kit, plus a variety of tuning pieces and the vent whistle and jet extensions.

Good Luck!
__________________
Jeff Taylor
Reply With Quote
  #12 (permalink)  
Old 09-17-2002, 08:16 AM
Mr.Fixit's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2002
Location: so cal, Cal
Cobra Make, Engine: I used to fix them for a living
Posts: 2,563
Not Ranked     
Default

Yes that is it. Instals on the metering block, facing out towards the fuel bowls. Up top, above the float. Do both bowls. I don't know why holley doesn't put these in all their carbs, it would cost three cents to do.
__________________
In a fit of 16 year old genius, I looked down through the carb while cranking it to see if fuel was flowing, and it was. Flowing straight up in a vapor cloud, around my head, on fire.
Reply With Quote
Reply



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

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 05:57 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy