Absolute Pace

Welcome to Club Cobra.

You are currently viewing the world's largest resource for Shelby related information as a guest which gives you limited access to view most discussions, articles and access our other FREE features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own photos and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!


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

Keith Craft Racing
Nevada Classics
Keith Craft Racing
Main Menu
Nevada Classics
Nevada Classics
Keith Craft Racing
Advertise at CC
Banner Ad Rates
MMG Superformance
MMG Superformance
Keith Craft Racing
October 2020
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 08-02-2003, 02:54 PM
gfi gfi is offline
CC Member
Visit my Photo Gallery

 
Join Date: Jul 2002
Location: Calgary, AB
Cobra Make, Engine: Naf/Arntz on a Shell Valley frame. 351 C Boss
Posts: 18
Not Ranked     
Default 351 Cleveland boss

Hi Folks:

I really have a dilemma and here's hoping someone can help. Just got a fresh 351 C Boss 850 Holley about 511 hp. Runs horrid: Only about 4.5 inches of vaccum at idle, have to feather to prevent from backfiring and get the idle up then it seems to get going ok. #2 problem is that I cannot seem to get the temp to stabilize. It just keeps climbing.

Any help or suggestions would be great.

Thanks

gary
Reply With Quote
Sponsored Links
Sponsored Links
  #2 (permalink)  
Old 08-03-2003, 01:59 AM
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: 5,407
Not Ranked     
Default

Clevelands can tend to run hot. I spent ages trying to get mine to behave itself. One thing that I found was a factor in getting the temp stable was ignition timing. Don't trust the timing marks on your balancer, I've been caught out before. Do a TDC test and mark your balancer with the right TDC. I drilled out and tapped an old spark plug and then put a bolt through it to make a piston stop to check it. I had the curve in my distributor reset and set it up with the specified static advance and most of my cooling problems went away.

I've found my Cleveland is happier with some water flowing through the heater hoses too. If you aren't running a heater you should conenct the 2 heater connections together.

For the motor to make 511HP it'll probably have a fairly big cam. Mine had a reasonable cam and ony pulled 10 inches at idle. With your Holley you might want to check what power valve you have in it. I've found that if the vacume at idle is very low the powervalve will open and dump way to much fuel into the motor. You will need to drop the power valve number to be under the level of vacume at idle to keep it shut. There are probably some people on here who have had more experience with Holleys than me so they may be able to confirm this.

Hope this helps.

Cheers
__________________
Mike Murphy
Melbourne Australia

Reply With Quote
  #3 (permalink)  
Old 08-03-2003, 08:19 AM
Bud Bud is offline
CC Member
Visit my Photo Gallery

 
Join Date: Dec 1999
Location: Stoneville, NC, USA,
Posts: 2
Not Ranked     
Default

Mine also ran hot until I added an aluminum oil pan, about 8 quart capacity, twin oil filters mounted behind the radiator, and an oil cooler. With the backfiring timing also sounds like a possibility.
Reply With Quote
  #4 (permalink)  
Old 08-03-2003, 05:11 PM
REPTYL's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2003
Location: Beaconsfield, Victoria, Australia, Vic
Cobra Make, Engine: RC_Sports Car Replica. Dodge Viper Blue, Candy apple Red stripes 408_Cleveland, 2v heads, twin Gas Research throttle bodies, Full manual stage 3 C10 auto, Jag 3.07 rear.
Posts: 972
Not Ranked     
Default

I run at a constant 195f. (the LPG likes it hot).
Mine's not a Boss though.
I can remember a fellow having a similar problem years ago and it had something to do with the Cleveland water channels not lining up with the Windsor block.
Something like that (can't remember the details)...

Last edited by REPTYL; 08-04-2003 at 01:57 PM..
Reply With Quote
  #5 (permalink)  
Old 08-04-2003, 05:23 AM
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: 5,407
Not Ranked     
Default

I always thought the Boss was the windsor block with Cleveland heads on it. I've been looking back through my Ford books and there actually was a Cleveland Boss produced in 1971. It had a 4 bolt bottom the same as the Cobra Jet version but with caps selected for hardness. The Heads were the same as the 4V and CJ but were machined for screw in studs and adjustable rockers and also ran heavier springs. The crank was cast Iron like all Clevelands but was selected for high nodularity. They had shot peened rods and better quality bolts. Forged 11.1:1 comp pistons. Cast aluminium manifold and "ram air" air cleaner.

All in all the motor sounds like a real factory hotrod. The later 72-73 HO motor shared many of the same parts as the Boss but ran a milder cam and only 9.2:1 comp.

Cheers
__________________
Mike Murphy
Melbourne Australia

Reply With Quote
Reply


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 05:12 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2020, 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