Absolute Pace

Go Back   Club Cobra > Club Forums > Australian Cobra Club

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
Advertise at CC
Banner Ad Rates
MMG Superformance
MMG Superformance
MMG Superformance
MMG Superformance
October 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 31    

Kirkham Motorsports

Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #1 (permalink)  
Old 09-22-2006, 08:21 AM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2006
Location: Darwin, NT
Cobra Make, Engine: King Cobra, QLD - 347 windsor
Posts: 308
Not Ranked     
Default Advice on LPG Impco setup

I've finally been given the thumbs up from Motor Vehicle Registry on my build, "in principle".

As far as the Impco setup is concerned, I want to run a dual quad inlet manifold and two Impco 425's, for my warmed up 302 windsor.

Is any one else running something close.

I need help on the throttle body sizes (base plates) I understand holley base plates required, but is a particular part better than others???

Photos of setups or instructions would be great.

Regards to all from the North.

Thanks, Hogster.
Reply With Quote
  #2 (permalink)  
Old 09-22-2006, 05:01 PM
Aussie Mike's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2001
Location: Sunbury, VIC
Cobra Make, Engine: Rat Rod Racer, LS1 & T56
Posts: 5,391
Not Ranked     
Default

I don't think it matters too much what size baseplate you use. The CA425 operates on vacume much like a CD stromberg. It has a diaphram that pulls a slide up allowing air to flow through. In the bottom of the slide is a cone shaped knob that meters how much gas is let through. A screw in the side of unit moves a plate back and forth to restrict the size of the opening and set your overall mixture. There's a seperate idle mixture circuit on the side which lets you set your idle mixture.

I believe there are a couple of different slides with different shaped end cones to give a couple of jetting options much like different needles for the jets in a SU or Stromberg carb.

A CA425 will only flow 425CFM wide open so the base plate probably doesn't matter too much. Smaller butterflys will give you a bit more throttle sensitivity. The mixer bolts directly to any of the Holley square bore base plates. I believe the 465 and 600 both have the same size butterflys under there.

I built one for my F100 years ago and just picked up an old Holley from a swap meet for $25. Take a vernier caliper with you to check the sizes of the butterflys if you are looking for a matching pair.

Most of the donor carbs that you will find at swap meets etc are Vac secondary but it's pretty straight forward to make them mechanical. A bit of welding on the linkage and an extra spring for the secondaries.

Cheers
__________________
Mike Murphy
Melbourne Australia

Reply With Quote
  #3 (permalink)  
Old 09-22-2006, 10:08 PM
Kanga's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2005
Posts: 106
Not Ranked     
Default

Hello, I run a single 425 on my F100, however I used a Rochester carb base plate and impco make an adapter plate to bolt the carb to the base plate. the Rochester has mechanical secondaries which are bigger than the primaries. With everything its all in the tunning, I think that at best the 425 is rated at about 300 hp Max

steve
Reply With Quote
  #4 (permalink)  
Old 09-23-2006, 03:11 AM
Gav's Avatar
Gav Gav is offline
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2006
Location: Mildura, vic
Cobra Make, Engine: FFR Coupe, 416ci of LS goodness
Posts: 2,349
Not Ranked     
Default

I have a mate who has removed a twin gas carb setup from his 350 Chev in a boat. He may be interested in selling the complete setup to you, get back to me if you are keen.
Gav
Reply With Quote
  #5 (permalink)  
Old 09-23-2006, 03:51 AM
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2006
Location: Darwin, NT
Cobra Make, Engine: King Cobra, QLD - 347 windsor
Posts: 308
Not Ranked     
Default

Yes Gav, I would be interested in a complete setup.

Thanks for the advice Mike and Steve. I fear that if it wasn't for the people like me being your wastegate from time to time, your brains will probably explode.

Thanks again
Hogster

Last edited by hogster; 09-23-2006 at 04:26 PM..
Reply With Quote
  #6 (permalink)  
Old 09-26-2006, 04:38 AM
Gav's Avatar
Gav Gav is offline
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2006
Location: Mildura, vic
Cobra Make, Engine: FFR Coupe, 416ci of LS goodness
Posts: 2,349
Not Ranked     
Default

Hogster,
Sorry for the delay but I had a bit of trouble getting in touch with the owner.
The system is a gas research twin gas carb arangement that has only done around 200hrs work.
One carb is a 400cfm unit and the secondry is 440cfm.
They are made to suit a spread bore manifold. The owner has everything, an 'end fill' 90ltr useable tank, 300mm round and 1500 long. It may not fit as it was made to fit behind the boats rear seat. The tachometric switch for the ignition and gas saftey shut off valves for tank and engine bay. The converter and all linkages and hoses. He also has extra jets and gas detection switchs that where in the bilge. you might want them for in the boot, or probably the bin.

Anyway he wants $1900 for the lot.
Give me a ring on 0407 110 641 if you are still keen.
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 04:56 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