Keith Craft Inc.- We service what we sell!!! Check out our Cobra engines!!! We build high performance racing engines and components for the fast pace strip racing industry as well as daily drivers who want to be FIRST!!!

FE Forums sponsored by Keith Craft Inc.


Welcome to Club Cobra.

You are currently viewing the world's largest resource for Shelby related information as a guest which gives you limited access to view most discussions, articles and access our other FREE features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!


Go Back   Club Cobra > Engine Building, Tuning, and Induction > FE 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

MMG Superformance
Nevada Classics
Keith Craft Racing
Main Menu
Nevada Classics
Nevada Classics
MMG Superformance
Advertise at CC
Banner Ad Rates
Keith Craft Racing
Keith Craft Racing
MMG Superformance
December 2022
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 31

Kirkham Motorsports

Like Tree16Likes

Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #41 (permalink)  
Old 09-20-2022, 07:36 PM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2020
Location: Baltimore, MD
Cobra Make, Engine: Everett Morrison FE 428
Posts: 87
Not Ranked     
Default

Patrick your not going to believe this,I did the rag test and they opened fully however I also removed the zip tie on drivers side and put a bread tie on the diaphragm rod before the test. I removed the rag and they did open fully on the second run. My zip tie was to wide, so anyone doing this test use a skinny zip tie. All and all the power wasn’t much different. I think I will have a dyno and tune session and maybe better sidepipes. Lastly a double pumper but I hope not. It was noted that Holley recommends DP for our cars, would it also benefit from a larger nozzle on vac sec? Thank you all for your help
Tommy and CompFi like this.
Reply With Quote
Sponsored Links
Sponsored Links
  #42 (permalink)  
Old 09-20-2022, 08:10 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,482
Not Ranked     
Default

That was a successful test. I know in our local club we have a set of shorties that we test with and scare neighbors with (they are not really side pipes at all more like two foot long side pipes). If your side pipes were extra restrictive, and since your engine is really just a big air pump, that could account for the reduced venturi air flow that you are seeing and the corresponding lack of power and inability to open the secondaries. So, I agree it's either the carb (which could still be just malfunctioning despite the fact that we got the secondaries to open with the rag test) or it's restrictive pipes. I think it's going to be one or the other so I would first try swapping out whichever part was the easiest for you to swap out. If the dyno guy could pop on some temporary straight pipes out of the primaries that would be lovely. If not, swapping on a mechanical secondary carb would be the next test. Let me ask you, is your Cobra loud enough? I know that's a subjective question but does it ever set off car alarms when you go by them parked on the street?
CompFi likes this.
Reply With Quote
  #43 (permalink)  
Old 09-21-2022, 07:51 AM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2020
Location: Baltimore, MD
Cobra Make, Engine: Everett Morrison FE 428
Posts: 87
Not Ranked     
Default

Maybe I wasn’t very clear but it was the wide zip tie being to tight and preventing sec from fully opening, with that off and a bread tie on they do fully open. My pipes are not overly loud in fact when I built it EM asked me if I wanted loud or louder I chose loud so I imagine they are more restrictive. What do you think of a larger Squirter? Before I try a DP.
Reply With Quote
  #44 (permalink)  
Old 09-21-2022, 07:53 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2022
Cobra Make, Engine:
Posts: 57
Not Ranked     
Default Truly grate thread

Learning so much from this thread.

Greatly appreciate All the insights and expertise shared here.

Congrats on the Success of an informative test!
Reply With Quote
  #45 (permalink)  
Old 09-21-2022, 08:43 AM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,482
Not Ranked     
Default

Quote:
Originally Posted by cobragene View Post
Maybe I wasn’t very clear but it was the wide zip tie being to tight and preventing sec from fully opening, with that off and a bread tie on they do fully open. My pipes are not overly loud in fact when I built it EM asked me if I wanted loud or louder I chose loud so I imagine they are more restrictive. What do you think of a larger Squirter? Before I try a DP.
Of course the squirter only squirts that one initial squirt when you hit the pedal and the little arm pushes the pump. After you've taken off, and that initial squirt has made in through to the cylinders, that's it for the accelerator pump. BUT, I encourage you to monkey around with the carb. Change the squirter, change the color of the cam, change which screw hole you use on the cam, none of that can really hurt anything and the more you do the more comfortable you get at doing it. The next easiest switch out will be to test a different carb, since it appears you're getting all you can out of the one you've got. But if you click my car's audio track here:

Click Here for My Car's Sound

Does your engine sound kind of like that, or would you say it's much quieter?
Reply With Quote
  #46 (permalink)  
Old 09-21-2022, 08:49 AM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2007
Location: Carlsbad, Ca
Cobra Make, Engine: SPF 2932 with 438 Lykins Motorsports engine. Previous owner of FFR 5452.
Posts: 2,568
Not Ranked     
Default

From the Holley website:
“For high performance engines a carburetor with mechanical secondaries has an inherent advantage over a carburetor with a “controlled” secondary system (air valve or vacuum diaphragm). This is possible because a controlled secondary carburetor, until it reaches wide open throttle, will not have as great a pressure drop below the throttle plates as would a mechani- cal secondary unit. The greater the pressure drop below the throttle plates the more dense will be the fuel/air charge to the engine and, hence, the more output.”

Swap out the carb and be done with it.
__________________
Jim
Reply With Quote
  #47 (permalink)  
Old 09-21-2022, 08:53 AM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,482
Not Ranked     
Default

Quote:
Originally Posted by jhv48 View Post

Swap out the carb and be done with it.
Noooo, half the fun of owning these cars is working on these cars. If you fix the problem immediately then you deprive yourself of continued satisfaction.
HTM101 likes this.
Reply With Quote
  #48 (permalink)  
Old 09-23-2022, 02:20 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2022
Cobra Make, Engine:
Posts: 57
Not Ranked     
Default Simply amazing......

Quote:
Originally Posted by patrickt View Post
Does your engine sound kind of like that, or would you say it's much quieter?
Sounds absolutely fantastic!!

Something truly missing from today's "flashlight" cars.
Reply With Quote
  #49 (permalink)  
Old 09-23-2022, 07:52 PM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2020
Location: Baltimore, MD
Cobra Make, Engine: Everett Morrison FE 428
Posts: 87
Not Ranked     
Default

I would say yours might be a tad louder, you have louder pops
Reply With Quote
  #50 (permalink)  
Old 09-23-2022, 07:58 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,482
Not Ranked     
Default

Quote:
Originally Posted by cobragene View Post
I would say yours might be a tad louder, you have louder pipes
OK, good to know. My side pipes have a just bit more baffling than the standard ones from Stainless Specialties (now long out of business of course) but not a whole lot. The standard ones are noticeably louder.
Reply With Quote
  #51 (permalink)  
Old 10-05-2022, 07:16 PM
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2020
Location: Baltimore, MD
Cobra Make, Engine: Everett Morrison FE 428
Posts: 87
Not Ranked     
Default

Update I purchased a cheap bore scope and the pipe going through the muffler is about 1.25”. I think I better get either 2.5 or 3” classic chamber pipes. I don’t want it ear shattering so should I consider 2.5 with packing or longer ones without? Can anyone recommend a shop I could send my collectors to and have them assembled? Patrick you have been a huge help and great teacher, thanks to the others input also.
Reply With Quote
  #52 (permalink)  
Old 10-06-2022, 12:05 PM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2007
Location: Carlsbad, Ca
Cobra Make, Engine: SPF 2932 with 438 Lykins Motorsports engine. Previous owner of FFR 5452.
Posts: 2,568
Not Ranked     
Default

I replaced mine with 3” internal baffles. Sounds like a top fuel dragster. Go with the 2 1/2” pipes if you don’t want to go deaf.
Still won’t solve your low on power problem.
That’s the carb.
__________________
Jim
Reply With Quote
  #53 (permalink)  
Old 10-06-2022, 07:14 PM
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2015
Posts: 138
Not Ranked     
Default

Quote:
Originally Posted by cobragene View Post
Update I purchased a cheap bore scope and the pipe going through the muffler is about 1.25”. I think I better get either 2.5 or 3” classic chamber pipes. I don’t want it ear shattering so should I consider 2.5 with packing or longer ones without? Can anyone recommend a shop I could send my collectors to and have them assembled? Patrick you have been a huge help and great teacher, thanks to the others input also.
I have the 3" Classic Chambered mufflers. They are quite loud. With my iphone/db app lying in my lap, idle is 94 db. 45 mph in 4th gear is 103 db. I began using ear plugs after the Classics were installed.
Reply With Quote
  #54 (permalink)  
Old 10-06-2022, 07:36 PM
patrickt's Avatar
Half-Ass Member
Visit my Photo Gallery

 
Join Date: Jun 2005
Cobra Make, Engine: ERA #732, 428FE (447 CID), TKO600, Solid Flat Tappet Cam, Tons of Aluminum
Posts: 21,482
Not Ranked     
Default

Mine are 95 dB at idle a foot away from the pipes. I really don't consider them too loud. These are the "quiet type" pipes from Stainless Specialties made about 17 years ago. They are quieter than a Harley, kind of as loud as maybe a big truck going slow up a hill if I'm ever so gentle on the throttle going down the street.

Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 10:45 PM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2022, 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