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.


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
Main Menu
Nevada Classics
Nevada Classics
MMG Superformance
Advertise at CC
Banner Ad Rates
Keith Craft Racing
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 Rate Thread Display Modes
  #1 (permalink)  
Old 04-22-2010, 01:11 PM
CC Member
Visit my Photo Gallery

 
Join Date: Sep 2007
Location: Marlboro, NJ
Cobra Make, Engine: Contemporary Cobra
Posts: 905
Not Ranked     
Default 2x4 vs 1 carb

I have 2x4 intake w/450's on my 428...beyond the WOW...would a singe holley and a RPM intake perform better?
Jon
Reply With Quote
  #2 (permalink)  
Old 04-22-2010, 01:40 PM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jul 2002
Cobra Make, Engine:
Posts: 15,712
Not Ranked     
Default

Perform better doing what? Single four will out perform dual fours at an auto cross or a tight twisty road race event. Dual fours might be better for a hill climb depending on cornering involved. Dual fours will outperform a single at Le Mans on the long straight away. I'd take duals over a single at the drag strip. On the street, the dual fours or single, your call.

In general, assuming intake manifolds are similiar design, the dual fours will make more horse power than the single four, in my opinion.
Reply With Quote
  #3 (permalink)  
Old 04-22-2010, 02:01 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: 21,897
Not Ranked     
Default

Center hung floats and the ability to use a Turkey Pan (for the looks alone) on the single outweigh the small horsepower gain that the duals give you, IMO.
Reply With Quote
  #4 (permalink)  
Old 04-22-2010, 02:17 PM
undy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2005
Location: Virginia Beach, Va & Port Charlotte, Fl.,
Posts: 2,280
Not Ranked     
Default

Given no hood clearance or other constraints a single carb will make more total HP than a dual quad setup.

I'm running dual 4s myself. The WOW factor is more than worth what small amount of HP you'll lose. I'm running a pair of Quickfuel custom built 750s on a Tunnel Wedge intake on my 482.
__________________
Too many toys?? never!
Reply With Quote
  #5 (permalink)  
Old 04-22-2010, 02:27 PM
RodKnock's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Feb 2007
Cobra Make, Engine: KMP 539, a Ton of Aluminum
Posts: 9,588
Not Ranked     
Default

Quote:
Originally Posted by patrickt View Post
Center hung floats and the ability to use a Turkey Pan (for the looks alone) on the single outweigh the small horsepower gain that the duals give you, IMO.
+1.

...may or may not give you.

I'm starting to sound like one of those old fuddy duddies, but the multi-carb musclecars of yesteryear had higher HP numbers than their single carb brethren, but the single carb cars usually beat their multi carb counterparts at the drag races.

Example: 1966 Corvette 427/425 HP (single carb) versus the 1967 Corvette 427/435 HP (Tri-power). Otherwise the same engine.

Disclamier: Every car, driver and engine are different.
Reply With Quote
  #6 (permalink)  
Old 04-22-2010, 03:02 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: 21,897
Not Ranked     
Default

Let me also throw in the fact that getting the linkage and synchronization on a single is a lot easier than on a double.
Reply With Quote
  #7 (permalink)  
Old 04-22-2010, 03:12 PM
Woodz428's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2003
Location: Freedomia,, Il
Cobra Make, Engine: Coupe,Blue w/white stripes SB; Roadster, Blue w/white stripes BB w/2-4s; SPF installer/Hot Rod-Custom Car builder
Posts: 1,376
Not Ranked     
Default

Unless you are running a drag specific intake, the single will in most cases out perform a comparably equipped 2-4 set up.. The bling is the thing. If you want the best performance a single is the way to go... I've run the trips and 2-4s and with the exception of the pure allure that a 2-4 offers, I think a single is better all around.
__________________
WDZ
Reply With Quote
  #8 (permalink)  
Old 04-22-2010, 04:43 PM
undy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2005
Location: Virginia Beach, Va & Port Charlotte, Fl.,
Posts: 2,280
Not Ranked     
Default

Quote:
Originally Posted by patrickt View Post
Let me also throw in the fact that getting the linkage and synchronization on a single is a lot easier than on a double.
roger that...
__________________
Too many toys?? never!
Reply With Quote
  #9 (permalink)  
Old 04-22-2010, 05:02 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2009
Location: Boise, Idaho, ID
Cobra Make, Engine: Contemporary Classics 427 SC, 427 sideoiler
Posts: 54
Not Ranked     
Default

Over the last 45 years, I've run everything from a single two bb to 6- 2bbl including 3x2, 2x4, 4x2. IMHO, a modern single bbl on a modern intake will make more hp everyday. Depends on what you want.....hp or bling.
Reply With Quote
  #10 (permalink)  
Old 04-22-2010, 07:04 PM
Ibr8k4vetts's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jan 2001
Location: Santa Barbara, Ca., ca
Cobra Make, Engine: R.U.C.C. with a 427FE, toploader
Posts: 1,435
Not Ranked     
Default

Quote:
Originally Posted by patrickt View Post
Let me also throw in the fact that getting the linkage and synchronization on a single is a lot easier than on a double.
Wow, I bolted my two 4"s on and maybe 15 minutes with a screwdriver done!
__________________
Mike Z
Nothing sucks more than that moment during an argument when you realize you’re wrong.
Reply With Quote
  #11 (permalink)  
Old 04-22-2010, 07:45 PM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jul 2002
Cobra Make, Engine:
Posts: 15,712
Not Ranked     
Default

Sheeshh Mike, I thought I was only one on this thread that could do that. Come on guys setting up the linkage for dual carbs aint that tough.
Reply With Quote
  #12 (permalink)  
Old 04-22-2010, 08:14 PM
Ibr8k4vetts's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jan 2001
Location: Santa Barbara, Ca., ca
Cobra Make, Engine: R.U.C.C. with a 427FE, toploader
Posts: 1,435
Not Ranked     
Default

Quote:
Originally Posted by Excaliber View Post
Sheeshh Mike, I thought I was only one on this thread that could do that. Come on guys setting up the linkage for dual carbs aint that tough.
I won't tell anyone
__________________
Mike Z
Nothing sucks more than that moment during an argument when you realize you’re wrong.
Reply With Quote
  #13 (permalink)  
Old 04-22-2010, 08:41 PM
RedCSX1's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2003
Location: Fresno, CA
Cobra Make, Engine: Shelby CSX 4766 (Vegas Built) with 482 Aluminum Pond motor
Posts: 814
Not Ranked     
Default

I had factory duals (600cfm's) on the 67 Gt500. What a pain, however the motor at that point was worn out and so was the carbs. I ended up switching to a single four. Just easier to live with but the dual certainly had a bigger WOW factor! Of course these day carb shops can build you a single carb that would outperform two carbs.
__________________
Morgan LeBlanc
Fresno CA
Reply With Quote
  #14 (permalink)  
Old 04-23-2010, 08:25 PM
Ibr8k4vetts's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jan 2001
Location: Santa Barbara, Ca., ca
Cobra Make, Engine: R.U.C.C. with a 427FE, toploader
Posts: 1,435
Not Ranked     
Default

I never said duels would out perform a single 4! all I said was setting up "new 2X4 is not that hard.
I am FAR form a pro, but are you sure they are 600 carbs? a lot of people tell me my carbs should be 600 but I believe 550 are correct?
__________________
Mike Z
Nothing sucks more than that moment during an argument when you realize you’re wrong.

Last edited by Ibr8k4vetts; 04-23-2010 at 08:29 PM..
Reply With Quote
  #15 (permalink)  
Old 04-23-2010, 09:09 PM
Hitch's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2009
Location: Clayton, NC
Cobra Make, Engine: BackDraft Racing 351W bored and stroked to 427 hydraulic full roller
Posts: 54
Not Ranked     
Default

More carbs = More problems..
Reply With Quote
  #16 (permalink)  
Old 04-24-2010, 04:51 AM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2003
Location: West Bloomfield, MI
Cobra Make, Engine:
Posts: 717
Not Ranked     
Default

Assuming equally well developed and tuned packages regarding engine and intake...

The side hung bowls on a single four are a distinct advantage in a road race environment.

The dual quads will outperform a single in a drag race environment - the advantages are better fuel distributon and equallized runner length.

Unfortunately the cast 2x4 intakes available for the FE are essentialy replicas of 40 year old parts and leave a lot of potential "on the table".
__________________
Survival Motorsports

"I can do that....."



Engine Masters Challenge Entries
91 octane - single 4bbl - mufflers
2008 - 429 cid FE HR - 675HP
2007 - 429 cid FE MR - 659HP
2006 - 434 cid FE MR - 678HP
2005 - 505 cid FE MR - 752HP
Reply With Quote
  #17 (permalink)  
Old 04-24-2010, 05:45 AM
mdross1's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Nov 2001
Location: Windham,, Me
Cobra Make, Engine:
Posts: 1,590
Not Ranked     
Default

All my dealings with multiple carbs and they always got changed out.My reason was off idle performance.Most all my battles were street and the single dailed in dbl pump was the only way to go.I do know friends running two fours that are very crispy just not for me.
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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 06:41 AM.


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