Club Cobra Gas - N Exhaust  

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

Keith Craft Racing
Nevada Classics
MMG Superformance
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Advertise at CC
Banner Ad Rates
Keith Craft Racing
MMG Superformance
MMG Superformance
March 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            
  #1 (permalink)  
Old 10-05-2012, 01:17 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default Gurney Weslake 305 Problems

I have a '69 305 Gurney Weslake with 4 48 IDA's.

I can get it to idle fine but when I barely get into it it bogs and pops and cuts out and wants to die. I dont know much about these webers and i have heard many ways to smooth out the progression from idle to mains.

right now im sitting on 65 idle jets with 120 holders. I drilled out the original 70 idle jets to about .8 and it helped a lot but then went way too large and wouldnt run at all.

When I push past the hole it runs great all the way through 8k rpm so I know my mains are good.

I have heard about drilling the third progression hole but im not sure I want to do that just yet. I also heard about making the idle holders a bit larger. Any ideas?
Reply With Quote
  #2 (permalink)  
Old 10-05-2012, 02:19 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

I'd start again at 60 idle, 100 holder.

How far out was your idle mixture screw with the 65s?
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #3 (permalink)  
Old 10-06-2012, 08:53 AM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

1 but I'm pretty sure it's starving for fuel
Reply With Quote
  #4 (permalink)  
Old 10-06-2012, 11:15 AM
Rick Parker's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2001
Location: California, Ca
Cobra Make, Engine: NAF 289 Slabside Early Comp Car with 289 Webers and all the goodies. Cancelling the efforts of several Priuses
Posts: 6,592
Not Ranked     
Default

Do what Gaz64 suggested, set all mixture screws at 3/4 - 7/8 of a turn open. If it idles ok at 800-1000 RPM but pops as the throttle is opened THEN it is lean. Leave main jets and associated air correctors alone until idle sytem problem is resolved. If it has been setting, the gas could have gone bad. I had a situation early this past Spring with some bad gas that created what is best descibed as scale in the tank. Minute pieces of it repeatedly ended up plugging various idle jets, causing it to run on 7 cylinders.
__________________
Rick

As you slide down the Banister of Life, may the splinters never be pointing the wrong way

Last edited by Rick Parker; 10-06-2012 at 11:38 AM..
Reply With Quote
  #5 (permalink)  
Old 10-06-2012, 12:13 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

The gas is new and I've spent 10 hours plus cleaning all the carbs. I have had the screws out in those locations and still same result.

I know for a fact it is lean because if it was rich it would still run much better than it does now. When I went up in size on the idle jets alone my hole was getting smaller but never got it decent. I'm wondering if the jets are ok but when I open it up a bit I can't flow enough through the holder..

If I need to get the 100 and 60 I will and I'm going to open up the 120 holder a bit and see what happens keeping te 65s. I know my main jet air corrector and emulsion are good so that's not an issue.
Reply With Quote
  #6 (permalink)  
Old 10-06-2012, 01:17 PM
Rick Parker's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2001
Location: California, Ca
Cobra Make, Engine: NAF 289 Slabside Early Comp Car with 289 Webers and all the goodies. Cancelling the efforts of several Priuses
Posts: 6,592
Not Ranked     
Default

If you open the holders it will become leaner (more air)
__________________
Rick

As you slide down the Banister of Life, may the splinters never be pointing the wrong way
Reply With Quote
  #7 (permalink)  
Old 10-06-2012, 01:20 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

The 120 holder is giving you lean progression.

Start small on both, get it to idle at 3/4 turn out on the screws, then open the throttle with the speed screw to check progression.

If the 100 holder can't richen progression, even with a 65 or 70 idle jet, you'll need the third progression hole drilled.

This is more common with 48 IDAs on a little engine. Makes driveability a concern for a street car.
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #8 (permalink)  
Old 10-06-2012, 08:26 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

Are there any good places to order the holders online? I'm going to epoxy and drill till I find out the right size.

How exactly do you drill te third progression hole? I've looked up a few sites but each one says something different. Plus I don't want to do it wrong (if I have to)
Reply With Quote
  #9 (permalink)  
Old 10-06-2012, 10:01 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

This may give some guidance:

Weber progression hole differences

third progression hole--Who drilled their own?
__________________
Gary

Gold Certified Holden Technician

Last edited by Gaz64; 10-06-2012 at 10:04 PM..
Reply With Quote
  #10 (permalink)  
Old 10-07-2012, 01:52 PM
Rick Parker's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2001
Location: California, Ca
Cobra Make, Engine: NAF 289 Slabside Early Comp Car with 289 Webers and all the goodies. Cancelling the efforts of several Priuses
Posts: 6,592
Not Ranked     
Default

302 cubic inches will RARELY require larger than a 65 idle jet. a 110 air holder will be about as lean as necessary too. Try a 60 jet with a 100 air holder. If the plugs are dark try a 110 air holder. If more fuel is needed go to a 65 jet and repeat. What emulsion tubes are you using?
__________________
Rick

As you slide down the Banister of Life, may the splinters never be pointing the wrong way
Reply With Quote
  #11 (permalink)  
Old 10-08-2012, 08:08 AM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

225 air corrector
f16 emulsion tube
170 main

I think....im at the office so I cant pull them to make sure.

keep in mind this is an Indy car motor, not an ordinary 302..

I really appreciate the help
Reply With Quote
  #12 (permalink)  
Old 10-09-2012, 07:55 AM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

What size choke in the carbs?

Strange jetting for a 305.

To me, I'd say wrong tube, main too big, and air WAY TOO big.
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #13 (permalink)  
Old 10-09-2012, 08:33 AM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

42 i believe

I called inglese, told them what I have and they (chuck) recommended the 225 f16 170 so I got them. now that ive invested hundreds and still am having problems i have decided to get advice from other sources.
Reply With Quote
  #14 (permalink)  
Old 10-09-2012, 01:25 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,773
Not Ranked     
Default

Can you give specs on the engine?
Compression ratio, camshaft, etc etc.


And just for comparison, although it's a sidedraught, they do work in the same manner, a 48 DCO 2/SP comes with the following:

http://www.ebay.com.au/itm/WEBER-48-...#ht_1335wt_907
__________________
Gary

Gold Certified Holden Technician

Last edited by Gaz64; 10-09-2012 at 01:30 PM..
Reply With Quote
  #15 (permalink)  
Old 10-09-2012, 01:51 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

i dont know the specs on the engine.

its an indy motor from 1969 made by gurney weslake from what i read 520 hp. i have a 400hp 1979 el camino and this motor is much much stronger.

ive researched all the specs and havent found anything yet.

its a very powerful and extremely high reving 305ci SBF 8,000 rpm+

you should hear it too
Reply With Quote
  #16 (permalink)  
Old 10-09-2012, 02:09 PM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2009
Location: Mendota, IL
Cobra Make, Engine:
Posts: 693
Not Ranked     
Default

I dont see very many weslake engines. Are you saying it is a set of Gurney Eagle heads on a 302 short block. A real Indy engine uses a lot of differnt Parts. I know they ran them in 1968 not sure about 1969 . I hve been running a set of mk IV's in my mustang. I built the engine in 1992. I dont run webers .In 1992 I got bits and pieces from twm. Mark
Reply With Quote
  #17 (permalink)  
Old 10-09-2012, 06:54 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

I drilled te holders out to .7 and it ran much better but was pouring black smoke so I'm going to keep going up till its better.

If it ran well with .7 and 65f10 is it possible I may be high on the idle jets?

I believe it to be an Indy car motor.
Reply With Quote
  #18 (permalink)  
Old 10-09-2012, 07:29 PM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2009
Location: Mendota, IL
Cobra Make, Engine:
Posts: 693
Not Ranked     
Default

So It should be very high compression. They ran on alcohol. Does this motor have a dry sump oiling system? Is it a new installation and you are just getting it running? What trans and rear gears? Is it in a Tbucket with a auto trans? Mark
Reply With Quote
  #19 (permalink)  
Old 10-09-2012, 07:52 PM
Rick Parker's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2001
Location: California, Ca
Cobra Make, Engine: NAF 289 Slabside Early Comp Car with 289 Webers and all the goodies. Cancelling the efforts of several Priuses
Posts: 6,592
Not Ranked     
Default

Continue to open the air holder in steps to a max of 110, change fuel jet to .60 after each air holder change and note change then replace with .65 fuel jet and go to next larger air holder size. As a rule 1 step in fuel jet equals 3 of air corrector. Changes of air corrector allow smaller increments of adjustment once correct fuel jet is determined. Emulsion tube creates transition before WOT.
__________________
Rick

As you slide down the Banister of Life, may the splinters never be pointing the wrong way
Reply With Quote
  #20 (permalink)  
Old 10-09-2012, 08:24 PM
23TGW's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Oct 2012
Location: Marion, TX
Cobra Make, Engine:
Posts: 19
Not Ranked     
Default

It doesn't have a dry sump. I bought the car recently and am trying to get it drive able. It has a c4 trans. I have no idea what gears. It's a jaguar rear end if I had to guess 4.10
Reply With Quote
Reply

Thread Tools
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

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 10:52 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
Links monetized by VigLink