Club Cobra GasN Exhaust  

Go Back   Club Cobra > Engine Building, Tuning, and Induction > Small Block Talk

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

Kirkham Motorsports

Like Tree2Likes
  • 1 Post By Tommy
  • 1 Post By RedHawk

Reply
 
LinkBack Thread Tools Rate Thread Display Modes
  #1 (permalink)  
Old 09-24-2016, 10:00 PM
Registered User
Visit my Photo Gallery

 
Join Date: Sep 2016
Cobra Make, Engine:
Posts: 3
Not Ranked     
Default 351w temp running very high

i am a newbie and have been learning as i go. I have a classic roadster with a 351w. the engine always seems to run hot and water temp gauge is always running up in the 225 range. I am starting to troubleshoot and will change the thermostat first. does anyone have any suggestions on the brand of thermostat to use and/or the degree (160/180/195etc...) that I should run? Thank you
Reply With Quote
  #2 (permalink)  
Old 09-24-2016, 10:33 PM
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2005
Location: Hillsboro, OR
Cobra Make, Engine: Scratch built CSX style frame, Carbon fiber body, 393 Stroker, T-bird IRS, T5
Posts: 1,623
Not Ranked     
Default

Are you running the proper rotation water pump? Did you get all of the air out of your cooling system when you filled it?
Reply With Quote
  #3 (permalink)  
Old 09-25-2016, 04:02 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,433
Not Ranked     
Default

And have you checked the accuracy of the temp gauge with an infrared temperature reader? On some cars the gauge will read high if the ground connection between the temp sensor and the engine block is not good (e.g., too much or wrong thread sealant on sensor).
Dwight likes this.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #4 (permalink)  
Old 09-25-2016, 04:10 AM
Registered User
Visit my Photo Gallery

 
Join Date: Sep 2016
Cobra Make, Engine:
Posts: 3
Not Ranked     
Default

Thank you Tommy and Three Peaks. I will also check these.
Reply With Quote
  #5 (permalink)  
Old 09-25-2016, 05:35 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,433
Not Ranked     
Default

spatt,
I gave the answer I did because its doubtful the thermostat is causing the problem unless it has failed in the closed position. If you do need a new thermostat, the standard factory item is set for 195 degrees I believe. I live in the deep south where high temps are common, so I opted for a 180 degree thermostat. I like to enter stop-and-go traffic with a little cooler temp so I have more room for it to rise before it gets worrisome.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #6 (permalink)  
Old 09-25-2016, 05:47 AM
Dwight's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: May 2001
Location: Florence, AL
Cobra Make, Engine: RCR GT 40 & 1966 Fairlane 390 5 speed
Posts: 4,511
Not Ranked     
Smile

I agreed with Tommy buy a good infrared temperature reader to check the temperatures at the thermostat. Then check the sending unit and compare the reading to the gauge.
I have found most are off some but others as much as 12 degrees.

Last spring while researching to replace a temp gauge that was off I found the company claim in their ad that their gauges could be 5% off and the sending unit could be 5% off. I called them and the tec told me the total could be 11%.

Dwight
__________________
''Life's tough.....it's even tougher if you're stupid.'' ~ John Wayne
"Happiness Is A Belt-Fed Weapon"
life's goal should be; "to be smarter than inanimate objects"
Reply With Quote
  #7 (permalink)  
Old 09-25-2016, 06:23 AM
Ron61's Avatar
Senior Club Cobra Member
Visit my Photo Gallery

 
Join Date: Dec 2001
Location: Shasta Lake, CA
Cobra Make, Engine:
Posts: 26,552
Not Ranked     
Default

The above answers are all good ones and if the engine is really running to hot you will notice a loss of power and possibly a smell of heated oil. We have Summer temperatures of 110/115 degrees here with humidity and my engine was designed to run at 200/210 and it never gets above that unless I run into stop and gpo traffic after running at freeway speeds for a while. Also if you do change the thermostat many people drill a small hole in the flange to let a little water through until it warms up and opens.

Ron
__________________
Ron 61
Ronnie Widener


View my Miscellaneous Gallery
Reply With Quote
  #8 (permalink)  
Old 10-01-2016, 07:36 AM
RedHawk's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2016
Location: Southlake, TX
Cobra Make, Engine: Classic Roadsters
Posts: 134
Not Ranked     
Default

I guess the question is does your overheating happen on highway or at 40 mph or under?

If its under 40 then I bet its your fan as it was with mine. Having the same setup as you I found out that the fan was wired inccorectly and the blades were rotating in the wrong direction essentially pulling hot air from engine and blowing it into the radiator. Once we identified this and properly wired the fan the temps have never climbed over 200.
Not saying its a improperly wired fan but it could be that your fan is not coming on while running properly at slower speeds or its not running enough cfms to cool coolant.
....or as mentioned above and more
Bad thermostat
Bad alternator not powering the fan
Bad fan or inadequate fan
Or need better radiator combo
Or dirty or rusted radiator coolant causing blockage
Wrong timing
Carb too rich or too lean-inspect plugs
Bad guage
Bad sending unit
Oversized pulleys running water pump to slow
Bad water pump
Air in coolant-need burp
Hose pinching
Over flow tank
Heat soak? Just threw that in. Need carb spacer
Ground cable somewhere is loose.

Hell I dont know, lol.
Dwight likes this.

Last edited by RedHawk; 10-01-2016 at 08:19 AM..
Reply With Quote
  #9 (permalink)  
Old 10-01-2016, 06:54 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

Quote:
Originally Posted by Tommy View Post
And have you checked the accuracy of the temp gauge with an infrared temperature reader? On some cars the gauge will read high if the ground connection between the temp sensor and the engine block is not good (e.g., too much or wrong thread sealant on sensor).
Most cars I know, if the temp sender has a poor ground (which is not common with a tapered thread) it causes the gauge to read lower than correct, not higher.

The sender is a NTC variable resistor, that becomes less resistance as the temperature rises. The gauge bimetallic strip is in series with the sender, the resistance change allows more current flow, then the gauge reads higher.

A common trick amongst "backyard mechanics" is to add a resistor in series with the sender to make the gauge read lower.

I found a car with a resistor added one day.

Took a lot of convincing to the owner they had a problem.
Reply With Quote
  #10 (permalink)  
Old 10-02-2016, 03:46 AM
Tommy's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Feb 2002
Location: Dadeville, AL
Cobra Make, Engine: Sold my EM.
Posts: 2,433
Not Ranked     
Default

Gaz64 is right. For example, it has long been difficult to get a temp sending unit that works right for my 1963 Corvette. About 15 years ago I added a resistor to the wire from my sender to get more accurate resistance readings to the original gauge. ... But, I recently removed the stock instrument panel and replaced it with a custom panel with new Speed Hut gauges. The Speed Hut temp sender has a two-wire connection with one wire connected to the body of the sender that is supposed to be grounded to the block. The gauge itself has its own power and ground connections. I found that a poor ground between the sender and the block caused intermittant high temp readings. It may be uncommon, but it can happen.
__________________
Tommy
Cheetah tribute completed 2021 (TommysCars.Weebly.com)
Previously owned EM Cobra
"Never attribute to malice that which is adequately explained by stupidity." - Hanlon's Razor
Reply With Quote
  #11 (permalink)  
Old 02-07-2017, 07:49 AM
bfreer's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jan 2005
Location: Powell, OH
Cobra Make, Engine: Classic Roadster II with 351W/TKO500
Posts: 77
Not Ranked     
Default

I also have temp problems with my 351W. After talking to some friends I will be installing a radiator fan shroud to assist my puller fan to work better. One of my friends had me move the fan closer to the radiator and that helped, but I think the shroud will completely fix my problem. Maybe you have a similar issue.
__________________
Life is not measured by the number of breaths we take, but by the moments that take our breath away.
Reply With Quote
  #12 (permalink)  
Old 02-07-2017, 10:51 AM
*13*'s Avatar
CC Member
Visit my Photo Gallery

 
Join Date: May 2006
Location: Portland, OR
Cobra Make, Engine: ERA FIA, 1964 289->Webers
Posts: 3,689
Not Ranked     
Default

Quote:
Originally Posted by spatt View Post
i am a newbie and have been learning as i go. I have a classic roadster with a 351w. the engine always seems to run hot and water temp gauge is always running up in the 225 range. I am starting to troubleshoot and will change the thermostat first. does anyone have any suggestions on the brand of thermostat to use and/or the degree (160/180/195etc...) that I should run? Thank you
Can you provide a picture of your setup? running hot can be a symptom of many things. Some could be obvious with a few simple pictures.

First Double check your timing. line the timing mark up & pull the number one plug. Make sure that piston is a the very top.
-make sure you have a high flow thermostat.
-make sure you have a big enough radiator & enough air pulling through it.
-yes,make sure the proper rotation pump is on the motor.

From there we can graduate to other possibilities.
__________________
ERA FIA 2088

Last edited by *13*; 02-07-2017 at 10:56 AM..
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 03:47 AM.


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