SUPPORT OUR SPONSOR

Go Back   Club Cobra > Club Cobra Tech Areas > Shop 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
MMG Superformance
Keith Craft Racing
Keith Craft Racing
Keith Craft Racing
January 2025
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 Display Modes
  #1 (permalink)  
Old 05-13-2003, 02:01 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default Really wierd timing issue

OK guru's, my timing when cold is 22* at idle, 34* total. When hot the timing is 40* at idle, 34* total. I tried it with the Jacob's box and the stock box. The distributor is a stock vacuum advance converted to mechanical advance. Could this be an out of phase issue? I shouldn't be the coil, the only other commonality. Any ideas?
__________________
Brent Dolphin
Reply With Quote
  #2 (permalink)  
Old 05-13-2003, 02:17 PM
Mr.Fixit's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2002
Location: so cal, Cal
Cobra Make, Engine: I used to fix them for a living
Posts: 2,563
Not Ranked     
Default

You have the vacuum advance disconnected, right?

All distributors have mechanical advance built into them, look under the rotor, there are little swing arms that fling out at rpm. Check those to make sure they are not sticky.
__________________
In a fit of 16 year old genius, I looked down through the carb while cranking it to see if fuel was flowing, and it was. Flowing straight up in a vapor cloud, around my head, on fire.
Reply With Quote
  #3 (permalink)  
Old 05-13-2003, 02:32 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default

The vacuum advance line is disconnected, and I also noticed it has a plug on it so if the air gets hot and expands it will push the vacuum plate. I thing that would retard the timing, but I removed it after I noticed it. I had it apart and the weights move freely and it works properly when the car is not warmed up. I don't know why the temp should matter.

I have another dist that has been sitting for a couple years in the block I just pulled from a friends motorhome. I guess I should pull it and clean it up and throw it in to check if you think the dist is the problem.

By converted to mechanical I just meant the proper springs were put in and the vacuum advance disconnected.

It is a magnetic pickup, would the heat affect the reluctor(?) and pickup?
__________________
Brent Dolphin
Reply With Quote
  #4 (permalink)  
Old 05-13-2003, 02:39 PM
Mr.Fixit's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Mar 2002
Location: so cal, Cal
Cobra Make, Engine: I used to fix them for a living
Posts: 2,563
Not Ranked     
Default

Well, the total timing is still 34 degrees at temp or cold, that is good. Why the initial timing appears to advance a bunch when hot is very, very odd. Maybe you ought to recheck it, that just doesn't seem right.
__________________
In a fit of 16 year old genius, I looked down through the carb while cranking it to see if fuel was flowing, and it was. Flowing straight up in a vapor cloud, around my head, on fire.
Reply With Quote
  #5 (permalink)  
Old 05-13-2003, 02:45 PM
Ron61's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Dec 2001
Location: Shasta Lake, CA
Cobra Make, Engine:
Posts: 26,597
Not Ranked     
Post

Brent,

I have an inductive distributor in my car and have ran it and the Jacob's Pro Street unit for years with no problems. Your problem seems odd but must be something simple. Did it just start or did you make any changes that could have changed things ?

Ron
__________________
Ron 61
Ronnie Widener


View my Miscellaneous Gallery
Reply With Quote
  #6 (permalink)  
Old 05-13-2003, 02:57 PM
Junket's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Apr 2002
Location: Klamath Falls, Or
Cobra Make, Engine: shell valley
Posts: 246
Not Ranked     
Default

Flipper are you attaching the pickup on the lite the same also some pickups don't like some after market wires stray RF before you change the distributor pull the plugs ( eat Wheaties) see if the timing chain has stretched how many degrees the crank moves + &- before the roter on the distributor does. Just a thought.
Ken
__________________
Talent is your head in communication with your balls.
Reply With Quote
  #7 (permalink)  
Old 05-13-2003, 02:58 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default

I only noticed this after getting the info to trigger directly from the dist and wiring it up. So I swithed back to the stock Orange box and got the same result. I switched back to the Jacob's and it's always the same. Check the timing cold = good, check the timing at operating temp = wierd. I wish I had a way to convert a video to the computer, I would post it for all to see.

On a side note, the Orange box retards my timing almost 8* at high rpm the piece of junk.

Maybe oil pressure or something as I would thing heat would retard everything at all rpm.
__________________
Brent Dolphin
Reply With Quote
  #8 (permalink)  
Old 05-13-2003, 03:10 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default

Junket, the timing chain is a double roller with 8000 miles. I would hope it hasn't stretched. I would think also the timing would be retarded if true.

Would the pickup/rotor being out of phase do this? I can drill a hole in an old cap if you y'all think I should check it.

I can watch the timing go from 40* at 1100rpm and it slowly retards to 34* at about 2800rpm. Weak springs and the added lube from the oild when it warms up? The springs aren't broken. Some sort of odd reversion. What would happen if I locked the advance, would this cause any engine problems? If the timing stayed steady with no ability to advance, I guess we would know it is in the weights/springs.
__________________
Brent Dolphin
Reply With Quote
  #9 (permalink)  
Old 05-15-2003, 01:06 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default

I swapped dists and the new one stayed at 22* and the idle quality was quite different. I guess I'll recurve the replacement dist.
__________________
Brent Dolphin
Reply With Quote
  #10 (permalink)  
Old 05-28-2003, 05:17 PM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jun 2001
Location: North Metro Atlanta, GA
Cobra Make, Engine: 2 dr roadster, V-8, 4 spd.
Posts: 2,780
Not Ranked     
Default

I once had the roll pin that holds/keys the star wheel inside the distributor disappear, and at random the star wheel would slip on the shaft of the distributor creating mistiming. Happen more when it was warm as things loosened up. Sounds like you are up and running, but for giggles, see if that star wheel has sloppy play.
Reply With Quote
  #11 (permalink)  
Old 05-28-2003, 05:55 PM
flipper35's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2001
Location: Southwest, WI
Cobra Make, Engine: Shell Valley, Mopar thingy (small block of course)
Posts: 2,215
Not Ranked     
Default

The only place there was any play is where the dist shaft goes into the gear. It's like a wide standard screwdriver and it didn't fit snug in the slot. The new one is rock solid, just the wrong curve.
__________________
Brent Dolphin
Reply With Quote
  #12 (permalink)  
Old 05-28-2003, 06:48 PM
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Jun 2001
Location: North Metro Atlanta, GA
Cobra Make, Engine: 2 dr roadster, V-8, 4 spd.
Posts: 2,780
Not Ranked     
Default

That'll do it.
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 On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 07:19 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, 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