Club Cobra Keith Craft Motorsports  

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

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
MMG Superformance
Main Menu
Module Jump:
Nevada Classics
Nevada Classics
Keith Craft Racing
MMG Superformance
Advertise at CC
Banner Ad Rates
MMG Superformance
Keith Craft Racing
MMG Superformance
May 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 Tree9Likes

Reply
 
LinkBack Thread Tools Display Modes
  #81 (permalink)  
Old 04-14-2014, 03:07 AM
*13*'s Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2006
Location: Tacoma, WA
Cobra Make, Engine: ERA FIA, 1964 289->Webers
Posts: 3,688
Not Ranked     
Default

The bracket sounds like a good idea. The outward fuel inlet manifolds are much more plentiful these days. There are a few of the others still around, though.
__________________
ERA FIA 2088
Reply With Quote
Sponsored Links
Sponsored Links
  #82 (permalink)  
Old 04-17-2014, 01:56 AM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,736
Not Ranked     
Default

Quote:
Originally Posted by jhirasak View Post
Hyde,

Thanks for sending your latest jetting spreadsheet to me. Just as a point of interest, I would like to mention the jetting and other changes that I had to make to a set of brand new 48 IDA Webers (out of the box from Redline) to get them to run smoothly on my car. They are as follows:

1. Adjust each float needle height to 25 mm by sanding the needle seat gasket (found a difference of up to 1 mm between the four carbs)
2. Adjust each float height setting after normalizing needle seat height
3. Adjust each carb air flow with butterflys closed so they indicate within 1 unit of each other reading on the air flow syncro meter (the general recommendation is to twist the throttle shaft to get the two throats to read the same value. I chose to drill small holes in the butterflys to get the same reading on all of the carbs)
4. Decrease Idle Jet holder from 120 to 100 to cure off idle transition hesitation
5. Adjust idle mixture screws to 1 1/8 turns from closed (different taper on idle mixture screw than earlier Webers?)
6. Change Emulsion Tube from F7 to F11 to correct for main jet transition richness (found problem by use of wideband O2 meter)
7. Change throttle linkage from as-provided single cross link to a bell crank arrangement to correct for left bank to right bank throttle position error (with single cross link arrangement, if both bank flow the same amount at idle, they would flow significantly different at 1800 to 2000 rpms, linkage geometry problem)
8. Change accelerator pump exhaust valve from 00 (blank) to 50 to correct for fuel dripping into the cylinders after hot shutdown (problem made worse by recent addition of alcohol in pump gas)

For anyone planning to install Webers on their car, I would highly recommend that they perform the first three steps listed above [u]before[u] they ever install them on the car for the first time.

John
John,

I beg to differ on point 8.

The exhaust valve with a STEEL inlet checkball is OPEN at rest so will not allow pump well pressure to overcome the pump nozzle outlet check ball, even after hot engine shutdown.

The nylon ball exhaust valve MIGHT have your mentioned phenomenon, but more than likely the carburettor is percolating. Solving the percolation issue is usually the best way.
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #83 (permalink)  
Old 04-17-2014, 06:34 AM
jhirasak's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2012
Location: Redondo Beach, CA
Cobra Make, Engine: 331 SB, AFR heads
Posts: 75
Not Ranked     
Default

GAZ64,

In my case, the pump exhaust valves that were provided with my new Webers all had a 00 bleed. This is a blank or closed exhaust valve and the gas inside the pump chamber has nowhere to go except out of the pump jet and into the throat of the carb in the event that the gas was heated above the vapor pressure of the alcohol that is currently being added to pump gas. By using a bleed valve which has a .50mm opening, any slowly expanding gas inside the pump chamber is allowed to return to the float bowl instead of dripping into throat of the carb.

Additionally, I have doubled the gaskets at the base of the carbs to reduce the amount of heat transfer from the manifold to the carbs. I also took the precaution to add an electric fuel pump that I could shut off some time before stopping the car to reduce the level of gas in the carbs. Some or all of these measures now appears to have corrected the problem of raw gas dripping into my engine after hot shutdown.

John
Reply With Quote
  #84 (permalink)  
Old 04-18-2014, 06:26 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,736
Not Ranked     
Default

John,

I still fail to see how fitting an exhaust valve of 00 (no bleed) causes your concern. The inlet ball is OPEN at rest, which will not allow pressure buildup within the pump chamber.

Similar to early Holley float bowls. They had a hanging steel inlet ball which seated by pump pressure. It had a .011-.013 open clearance.
The late Holley bowls have a viton rubber inlet valve AND a .010 vapor bleed back to the bowl. Without the bleed (or blocked), the pump can discharge as the engine heatsoaks.
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #85 (permalink)  
Old 04-18-2014, 07:26 PM
jhirasak's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2012
Location: Redondo Beach, CA
Cobra Make, Engine: 331 SB, AFR heads
Posts: 75
Not Ranked     
Default

Gday Gary,

I think that when the gas in the pump chamber starts to percolate, it provides sufficient pressure to seat the inlet check valve and, without a bleed outlet, the gas and expanding vapor bubble pushes the gas inside the pump chamber out of the jet into the throat of the carb. That is a guess on my part as what was going on. In any event, after I changed to a bleed valve with a .50mm orifice, my fuel dripping problem became a bad memory in the past.

Since you live down under, do you have alcohol added to your pump gas by mandate of the government? The justification by the authorities was that this was added to our gas to reduce emissions problems. I am not sure about the validity of their explanation regarding the reduction of emissions but I am sure that it has caused us some corrosion and driveability problems with older cars.

Cheers Mate,

John
Reply With Quote
  #86 (permalink)  
Old 04-20-2014, 05:13 PM
PaulProe's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2006
Location: Manchester, MO
Cobra Make, Engine: Hurricane - FE
Posts: 603
Not Ranked     
Default Big Block Guys

Thanks, Hyde, for the copy of the jetting survey. A question for you and the others on the forum:

There are only 5 entries for the big block cars, mine being the sixth. Are there not more guys who have Webers on a big block? How about posting your specs so we can get a wider sampling

Paul
__________________
www.65shlb.com
www.prdcrrct.com
Reply With Quote
  #87 (permalink)  
Old 04-20-2014, 07:50 PM
Gaz64's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2008
Location: Brisbane, QLD
Cobra Make, Engine:
Posts: 2,736
Not Ranked     
Default

Quote:
Originally Posted by jhirasak View Post
Gday Gary,

I think that when the gas in the pump chamber starts to percolate, it provides sufficient pressure to seat the inlet check valve and, without a bleed outlet, the gas and expanding vapor bubble pushes the gas inside the pump chamber out of the jet into the throat of the carb. That is a guess on my part as what was going on. In any event, after I changed to a bleed valve with a .50mm orifice, my fuel dripping problem became a bad memory in the past.

Since you live down under, do you have alcohol added to your pump gas by mandate of the government? The justification by the authorities was that this was added to our gas to reduce emissions problems. I am not sure about the validity of their explanation regarding the reduction of emissions but I am sure that it has caused us some corrosion and driveability problems with older cars.

Cheers Mate,

John
Hi John,

I see your point, and if it works for you, then you must have had nylon check valves in the 00 pump exhaust valves. The nylon balls seat faster then steel.

We have had ethanol blended fuels for some time now, it's a lottery what you get now.
__________________
Gary

Gold Certified Holden Technician
Reply With Quote
  #88 (permalink)  
Old 04-21-2014, 02:35 AM
*13*'s Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2006
Location: Tacoma, WA
Cobra Make, Engine: ERA FIA, 1964 289->Webers
Posts: 3,688
Not Ranked     
Default

Quote:
Originally Posted by PaulProe View Post
Thanks, Hyde, for the copy of the jetting survey. A question for you and the others on the forum:

There are only 5 entries for the big block cars, mine being the sixth. Are there not more guys who have Webers on a big block? How about posting your specs so we can get a wider sampling

Paul
At the time I put this together, I requested info. What you see, is what I recieved.
What is needed is a web page where people can submit their specs & it will automatically post into a chart. I certainly don't have the resources. It may get a little more attention, though.
__________________
ERA FIA 2088
Reply With Quote
  #89 (permalink)  
Old 08-16-2021, 09:05 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

Quote:
Originally Posted by *13* View Post
At the time I put this together, I requested info. What you see, is what I recieved.
What is needed is a web page where people can submit their specs & it will automatically post into a chart. I certainly don't have the resources. It may get a little more attention, though.
"13"

Can we resurect this thread? It would be helpful to new Weber new-be's.

Thanks,

Jim
cobra likes this.
Reply With Quote
  #90 (permalink)  
Old 09-11-2021, 09:54 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2003
Cobra Make, Engine: Unique Motorcars 289 USRRC, 1964 289 stroked to 331, toploader
Posts: 837
Not Ranked     
Question

Hyde,


Is the photo of the spreadsheet in post 65 the complete database or is there a file for download somewhere?


PS, thought you were somewhere around Vergennes...


Thanks!
__________________

Paul

Unique Motorcars 289 USRRC
1964 289 5-bolt block
Toploader and 3.31 rear
Reply With Quote
  #91 (permalink)  
Old 09-29-2021, 11:40 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

Hi Paul,

I would like to get this discussion going again if you would like to help. I just recently added 48IDA's to my mild 289 in a FFR roadster that I used to run a Holly 570 on it. What a difference Webers make! I still don't have them tuned perfect but good enough to drive in traffic and have some real fun out on the open road.

Jim in Pa
Reply With Quote
  #92 (permalink)  
Old 09-30-2021, 11:50 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2003
Cobra Make, Engine: Unique Motorcars 289 USRRC, 1964 289 stroked to 331, toploader
Posts: 837
Not Ranked     
Thumbs up Hopefully!

Agreed, Jim, but I am still a ways out on getting my set up. I was hoping to hear from Hyde before now, to keep a file on what success others have been having with their setups. He was once quite active here... hasn't been back since the end of July.
__________________

Paul

Unique Motorcars 289 USRRC
1964 289 5-bolt block
Toploader and 3.31 rear
Reply With Quote
  #93 (permalink)  
Old 10-01-2021, 09:38 AM
zimmy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2000
Location: Leesburg, VA USA, VA
Cobra Make, Engine: Contemporary, 427 FE Center Oiler w/ 48 IDA Webers
Posts: 237
Send a message via AIM to zimmy
Not Ranked     
Default

Check with Jim Inglese. jiminglese@att.net
Reply With Quote
  #94 (permalink)  
Old 10-01-2021, 11:43 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

We're looking for a discusion here on others experience with webers.
Reply With Quote
  #95 (permalink)  
Old 10-03-2021, 09:25 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

Yesterday I spent some time ballancing my 48 IDA's as I was having some poping out of the driver side pipe. Part of the linkage between the left and right carbs had loosened up since I had not tightened one lock nut securely. Then I reset best idle on all carbs. I then took it on a 30 mile trip to see a friend and it ran so good I couldn't belive the difference. Having the carbs ballanced front to back and side to side is the real secret to getting your setup running great. I run 90 octane gas btw.

Jim in Pa.

Paul, if you have any questions please let me know and I will try to answer them based on my experience, but I am not an expert by any means. I have only this summers' driving time to relate to you.

Last edited by 65arboc; 10-03-2021 at 09:29 AM..
Reply With Quote
  #96 (permalink)  
Old 10-03-2021, 09:37 AM
1795's Avatar
CC Member/Contributor
Visit my Photo Gallery
Gold Star Contributor
 
Join Date: Aug 2013
Location: Canandaigua, NY
Cobra Make, Engine: SPF MKII Riverside Racer FIA
Posts: 2,286
Not Ranked     
Default

Whenever I am approached at the track by people who are interested in Webers, but have heard horror stories about how difficult it is to get them set right, I tell them that it is not that difficult, they are easy to adjust, and the most crucial piece is to have a strong and stable linkage. Linkages that are loose, or not well stabilized or use components that can be stretched are a recipe for disaster.

I had to add some further bracing to the support that comes up from the back of the head that connects the throttle arm to the arm that then connects to the linkage going down between the carbs as it would twist a little under hard acceleration and the car would not run right. Since stabilizing that support, no problems.

Jim
__________________
Reply With Quote
  #97 (permalink)  
Old 10-05-2021, 07:53 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

Quote:
Originally Posted by 1795 View Post
Whenever I am approached at the track by people who are interested in Webers, but have heard horror stories about how difficult it is to get them set right, I tell them that it is not that difficult, they are easy to adjust, and the most crucial piece is to have a strong and stable linkage. Linkages that are loose, or not well stabilized or use components that can be stretched are a recipe for disaster.

I had to add some further bracing to the support that comes up from the back of the head that connects the throttle arm to the arm that then connects to the linkage going down between the carbs as it would twist a little under hard acceleration and the car would not run right. Since stabilizing that support, no problems.

Jim
Hi Jim,

Very good information. This is what I would like to see here, others experience with their Webers to help new owners get their setup sorted out.

Thanks Jim for your input.

Jim in Pa
Reply With Quote
  #98 (permalink)  
Old 10-05-2021, 08:44 AM
svassh's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2021
Cobra Make, Engine: FF MK2 with 347 Ford and 4 Webers
Posts: 16
Not Ranked     
Default

Not an expert myself but will share some notes that I have gathered from various internet sources and emails/calls with Jim Inglese. I am running a Redline manifold on a 347 with Weber 44 IDF carbs.

Weber 44 IDF Setup
Main jets – 145
Idle jets - .65
Emulsion Tubes – F11
Air Corrector – 175
Floats – 11mm open without ball valve being depressed

My timing is all in early before 3K RPM at 38 degrees BTDC and roughly 20 degrees initial.

1. With motor off, Disconnect linkage between carb left and right side
2. Back idle speed screws out till not touching, then turn in turn on each bank
3. Set idle mixture screws to or 7/8 turn out from seated
4. Start motor
5. Synch carbs on each side using only adjustment screw on linkage between carb banks
6. Reconnect linkage between carb banks
7. Adjust linkage between banks till left and right side banks are in synch then lock down linkage
8. To set best lean mixture, for each cylinder
a. Turn idle mixture screw out 1/8 turn
i. If idle speed increases stop, if not repeat 8a till idle speed increases then stop
ii. If idle speed decreases or does not increase, turn idle mixture screw in 1/8 turn till idle decreases then back off 1/8 turn
b. Repeat for each cylinder
9. Check each spark plug condition after driving for lean or rich, adjust each cylinder as needed. 1/8 turn in on idle mixture screw if rich, 1/8 turn out if lean.
10. If you have a flat spot during transition from idle to main circuit, back each idle mixture screw out 1/8 turn.

I can tell you I spent weeks messing with different idle jets only to discover what a significant impact timing has on these setups. I have since gone to a locked out MSD Distributor at 40 degrees and control the timing curve with an MSD 6AL2 Programmable ignition box. Too much or not enough timing will cause a stumble thru the transition phase that you will swear is an idle jet problem. My car is very docile and predictable at low RPMs and all thru the transition curve to 3K RPM with light throttle and will climb thru the RPMS quickly with heavy throttle. I have found with my setup I do need to run slightly rich or I will get lean pops in the sidepipes under light acceleration and deceleration.

Some web links for helpful reference:
http://www.redlineweber.com/html/Tec...t_controls.htm
https://www.racetep.com/manufacturer...ber-carbs.html
https://www.gt40s.com/threads/weber-...youtube.32276/
http://www.timsroadster.com/html/tuning_webers.html
Ignition Timing and Webers
https://jiminglese.com/common-questions
https://jiminglese.com/weber-tech
https://www.gt40s.com/threads/weber-help-please.41056/

Last edited by svassh; 10-05-2021 at 09:08 AM..
Reply With Quote
  #99 (permalink)  
Old 10-10-2021, 08:23 AM
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2021
Location: Warren, PA
Cobra Make, Engine: Factory Five MK 4 289 HI Po with Webers
Posts: 19
Not Ranked     
Default

Here are my final specs and the engine is running great like never before. Just a little rich at 1000 rpm idle.

Engine is a 289 bored .030 over
Heads are iron stock but with upgraded valve seats.
Manifold is from Redline Weber
Mild Grind Cam from Comps
Carbs are 48IDA
Choke are 37mm
Idle jet holder-120
Idle Jet-F-10-65
Air Corrector Jet-195
Main Emulsion Tube-F-7
Main Jet-180
Pump Exhaust Valve is Non Ported

Hope this helps someone else.

Jim in Pa

Last edited by 65arboc; 10-10-2021 at 08:27 AM..
Reply With Quote
  #100 (permalink)  
Old 10-28-2021, 05:56 AM
priobe's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2004
Location: miami, FL
Cobra Make, Engine: E-M Cobra Ford FE 427 w/ Webers 48 IDA
Posts: 1,368
Not Ranked     
Default

Hello All
It’s been a while since I’ve posted. I came across this website and checked it against my settings. It’s not perfect but you will never find a perfect recipe for any setup. It will be a fine tune trial and error.

I hope it helps put some one in the ballpark to get started

https://www.carbparts.eu/calc

Sorry if this was mentioned already.
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 12:45 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
Links monetized by VigLink