Runs Too Hot
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 876
Likes: 1
From: Same as our leaders Out of my mind
Runs Too Hot
OK - So I thought a new 4 core brass/copper radiator with a nice new fan shroud, thermostat and water pump should keep everything cool. WRONG! My temp gauge is reading up to 240 degrees. What is the best way to go without going overboard? Is a 2 core aluminum radiator going to be that much better? Do I need to add electric fans? Will a high volume water pump make a difference? Or is it "D" all of the above? 
Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,374
From: At my Bar drinking and wrenching in Lafayette Colorado
Check your timing and make sure you have your vacuum advance hooked up and operational (running off manifold vacuum). Retarded timing or inoperable vacuum advance will run the temp right up there. With the vacuum advance hooked up, you should see timing at idle of about 32-34 degrees, and this will give you the coolest running engine possible.
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
Check the gage
You really need to see what you REALLY have in terms of heat. The best investment is getting one of those little lazer temp thingys, a pyrometer or something. They are only about $70. Then move forward. I ended up with a new high flow pump, Alum rad from Dewitts, etc, etc. I spent alot of time and $ on the whole affair. Its not as easy as one might think. Make sure that ALL of your seals are in place run a 20/80 mix and maybe throw some water wetter in too.
The gauges are crap too....
Good luck
carbster
The gauges are crap too....
Good luck
carbster
Le Mans Master
Joined: Mar 2002
Posts: 6,217
Likes: 1
From: End of the Ike IL
Cruise-In V Veteran
Cruise-In VI Veteran
Originally Posted by icanfixitforyou
No - do you know where I can get them? 
Intermediate
Joined: Sep 2005
Posts: 44
Likes: 0
Originally Posted by lars
Check your timing and make sure you have your vacuum advance hooked up and operational (running off manifold vacuum). Retarded timing or inoperable vacuum advance will run the temp right up there. With the vacuum advance hooked up, you should see timing at idle of about 32-34 degrees, and this will give you the coolest running engine possible.
Don't want to hijack this thread, but I have been chasing cooling problems also. How can I check the vacuum advance?
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
When does it get this hot??? City? Highway? Idle? If its while driving do you have the factory front spoiler??? The spoiler is crucial....its not just for looks...it directs the air up to the rad.
Jim
Jim
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Recomendations;
Make sure timing is all correct
Make sure no air in cooling system
Make sure seals on Rad are all in place
Air Dam must be used(it only works at speed tho)
Electrical fans are a nice way to go, they work in traffic
Make sure Mechanical fan and clutch are working correctly
Make Sure Guage is reading correctly, Pyrometer as mentioned above is a good way to go, handy for all kind of stuff
Those are the basics, cover those bases and see where you are then
I am going to go with Aluminum Rad and electric fans with a soft start kit, the rad in my car is a 2 row brass and copper, not good enough for south florida traffic. Should keep it nice n cool even with air on in traffic.
Make sure timing is all correct
Make sure no air in cooling system
Make sure seals on Rad are all in place
Air Dam must be used(it only works at speed tho)
Electrical fans are a nice way to go, they work in traffic
Make sure Mechanical fan and clutch are working correctly
Make Sure Guage is reading correctly, Pyrometer as mentioned above is a good way to go, handy for all kind of stuff
Those are the basics, cover those bases and see where you are then
I am going to go with Aluminum Rad and electric fans with a soft start kit, the rad in my car is a 2 row brass and copper, not good enough for south florida traffic. Should keep it nice n cool even with air on in traffic.
Safety Car
Joined: Dec 2004
Posts: 4,876
Likes: 1
From: Jersey Shore Exit 98
Check the fan clutch. Double check that the thermostat is sitting in the correct direction to the radiator. Last thing, my vette ran at 220 all the time I added 40 below radiator treatment now I run at 200 even all year round.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
Originally Posted by carbster09
You really need to see what you REALLY have in terms of heat. The best investment is getting one of those little lazer temp thingys, a pyrometer or something. They are only about $70. Then move forward. I ended up with a new high flow pump, Alum rad from Dewitts, etc, etc. I spent alot of time and $ on the whole affair. Its not as easy as one might think. Make sure that ALL of your seals are in place run a 20/80 mix and maybe throw some water wetter in too.
The gauges are crap too....
Good luck
carbster
The gauges are crap too....
Good luck
carbster
Last edited by kb2fzq; Feb 9, 2006 at 09:33 AM.
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
Originally Posted by icanfixitforyou
OK - So I thought a new 4 core brass/copper radiator with a nice new fan shroud, thermostat and water pump should keep everything cool. WRONG! My temp gauge is reading up to 240 degrees. What is the best way to go without going overboard? Is a 2 core aluminum radiator going to be that much better? Do I need to add electric fans? Will a high volume water pump make a difference? Or is it "D" all of the above?
I'll bet your not running 240! All the temp sending units sold at auto parts store are wrong for the gauges and when they go over 180, the reading goes nuts. 5 over reads 15, 10 over reads 30, and so on. As recommended here, buy, steal, or borrow an IR gun. Confirm the reading before doing anything. If the sending unit is off, find the old GM one or buy a new one from lectric limited, they claim to work correctly.
The Vaccum can is easy to check. Hook up a timing light and do the timing as usual, with the vacuum hose plugged. Set the timing per the specs and lock down the distributor. Then, when you re-connect the hose to the vaccum can, it should jump another 12-15 degrees advanced. If not, the diapham is broke and it isn't working. The symptoms of a dead vacuum can are over heating at idle and running cool at high speeds.
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 876
Likes: 1
From: Same as our leaders Out of my mind
Thanks for the information! I have ordered a radiator/shroud seal kit from DocRebuild, and found a new 16" 2500 cfm electric fan online (for under $50.00). Between the two, and checking the timing (mine is ported at the carburetor, does that make a difference?) I hope to get this issue under control. My overheating problem occurs at highway speeds only. I am turning rather high rpm's due to the 3:73 rear and the 1:1 5th gear in the Richmond trans. Off the line and for the short run the car is awesome (just ask the guy in the pro lincoln coupe!) but on the highway it leaves something to be desired. A change to a 3:08 rear is in the very near future, hopefully that will help with the heat as well. All of your feedback is greatly appreciated. Save the Wave!
East bound and down...
Joined: Dec 2004
Posts: 987
Likes: 3
From: Jonesboro Arkansas
Originally Posted by BlueL36
I got mine from DocRebuild, but there are other vendors that have them specific to your 'vette. The seals force the air through the radiator and does not allow the air to go around it. Good Luck!
The seals make a big difference. Dr. Rebuild is the place to go for those.
Tech Contributor
Joined: Aug 1999
Posts: 14,375
Likes: 6,374
From: At my Bar drinking and wrenching in Lafayette Colorado
Originally Posted by Bass
Don't want to hijack this thread, but I have been chasing cooling problems also. How can I check the vacuum advance?
