My big block Nova is over heating HELP ! - Hot Rod Forum : Hotrodders Bulletin Board -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans Advertise
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
lost password?   |   register now

LinkBack Thread Tools
  #1 (permalink)  
Old 07-22-2006, 04:08 PM
71 nova's Avatar
Registered User
Join Date: Jul 2004
Location: Port Huron
Age: 66
Posts: 18
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
My big block Nova is over heating HELP !

Help I have an Over heating problem !

My 71 Nova is over heating the temp gauge will slowly creep up to 230+ degrees when in sitting at an idle. The temp stays around 200 when the car is moving and cools quickly to this temp. Here is the background on this car. The engine is a very mild ( almost stock ) big block 454. The car is not running headers it still has the stock exhaust manifolds with flow masters. I have a Jeg's aluminum 2 row radiator with 1 inch tubes about 27"x 19" a Jeg's high volume water pump, and 195* thermostat using distilled water . I also have a small, but full fan shroud and a aluminum flex fan.

The engine timining is fine and I am running a 750 holley carb. When the car is running at idle I can feel good air flow from the fan and I can see good water flow in the radiator, but still this thing is running too hot, and yes the gauge is correct. Any ideas? I have been fighting this problem for a while and I am at a loss here! Thank you in advance for any help you can provide?.

Reply With Quote Quick reply to this message
Sponsored Links
  #2 (permalink)  
Old 07-22-2006, 04:57 PM

Last journal entry: Wiring finished finally
Join Date: Jul 2005
Posts: 584
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Imo, I would scrap that flex fan. Don't like them, instead, swap to a good ol' fashion steel clutch fan and you'll save some horsepower as well since you will have the clutch setup and should flow much better as well.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-22-2006, 05:32 PM
Bryan59EC's Avatar
Car? Truck? Who Cares

Last journal entry: First week of December
Join Date: Jun 2006
Location: San Antonio, Texas
Age: 60
Posts: 2,485
Wiki Edits: 0

Thanks: 6
Thanked 77 Times in 58 Posts
Classix & I both feel your pain We both have 454s in our elkys-I think he has solved his issue---But mine is still not running as cool as I would like.
Clutch fan would be a good start, but also check to see if the air can get OUT of the engine bay. My next step is to remove the A-arm seals for added ventilation, I also have an aluminum 2-core radiator but I have dual electric fans. I have not yet seen 220 at idle with the a/c running and I do get cooled down to 190-195 while moving. Living in So. Tx. gets damn hot here and also humidity is not my friend. I would probably run cooler in Phoenix at 115 than I do here at 100.
I would think that a properly shrouded engine driven clutch fan should help greatly, since you are only having the problems in traffic or at idle.


200 is okay given you have a 195 t-stat.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-22-2006, 09:29 PM
Deuce's Avatar
Registered User
Last wiki edit: Choosing a trailer
Last journal entry: Jan 13 2013
Join Date: Aug 2002
Location: Deuceland USA
Age: 72
Posts: 5,653
Wiki Edits: 6

Thanks: 0
Thanked 11 Times in 10 Posts
I bought a 1969 Nova Super Sport with the 396/375 horsepower option ... NEW ... and they came with a 4 row radiator. NOT a 2 row ... They had a 7 blade belt driven fan and a shroud. Within 90 days of purchase it was a 427 BBC and within a year it had a 454/450 LS - 6 motor ... even here in the hot and humid SOUTH ... it would run 190 or so ... no problems ... with the BIG radiator.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-23-2006, 10:28 AM
Join Date: Jan 2005
Posts: 1,070
Wiki Edits: 0

Thanks: 0
Thanked 2 Times in 2 Posts
I agree a 6 or 7blade clutch fan and a BIG radiator. I built 403 Olds that with the a/c on would go 210 (gets hot & humid in nebraska too) a buddie of mine owns a radiator shop (been best friends since grade school ) I told him and he he said pull it in the shop and pop the hood, he pulled a 4 row radiator out of a box put it in the Olds with antifreeze . Problem solved. I'm was running a 7blade clutch fan too.

Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-23-2006, 10:33 AM
xntrik's Avatar
Save a horse, Ride a Cowboy.
Join Date: Jul 2005
Location: Arkansas
Posts: 5,122
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
It sounds like you have a good radiator and water pump.
Your water pump should be overdriven 10%.

Definitely a thermostatic fan clutch and 7 blade fan with the blades 3/4 inch maximum inside the shroud. Seal your radiator area so that at low speeds the hot air is not recirculated back into the front of the radiator or under the bumper.

If you have to use a flex fan, go to and keep clicking on the flex fan pictures. You will eventually come to the big stainless flex fans. The blade twist begins with the hub and they move lots of air with very little hp loss. I have used these and have had excellent results.

You might read through this thread for addtional ideas.

Last edited by xntrik; 07-23-2006 at 10:38 AM.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may 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

Similar Threads
Thread Thread Starter Forum Replies Last Post
the history of chevy v8's savman1 Hotrodders' Lounge 43 03-02-2012 06:57 PM
427 Big block blew up, need a few suggestions. esears Engine 17 03-12-2007 08:18 AM
72 Nova 454 Radiator & Water Pump leejoy Engine 10 12-09-2005 05:12 PM
69 Camaro Big Block Underhood Photos?? EricTopless68 Camaro Engine 4 03-10-2004 06:03 PM
header clearance on a big block nova Super69Nova Engine 4 07-11-2003 01:33 PM

All times are GMT -6. The time now is 11:24 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.