Overheating big block
Thread Starter
Intermediate
Joined: Aug 2017
Posts: 33
Likes: 4
From: South Florida
Overheating big block
Alright so I have a 1979 corvette with a BBC 540 and I can’t get the thing to run cool.
I have a 4 core champion radiator running a 80/20 mix with water wetter added to it.
Dual maradyne electric fans with shroud about 3500cfm
Stewart stage 2 aluminum water pump with a march under drive pulley.
Timing is set at 18 initial with mechanical advance all the way to 38 at 3000rpm
165 thermostat that is operational and doesn’t stick(confirmed in boiling water)
Car runs great but temps consistently climb past 220 with ease. Am I missing something?
I have a 4 core champion radiator running a 80/20 mix with water wetter added to it.
Dual maradyne electric fans with shroud about 3500cfm
Stewart stage 2 aluminum water pump with a march under drive pulley.
Timing is set at 18 initial with mechanical advance all the way to 38 at 3000rpm
165 thermostat that is operational and doesn’t stick(confirmed in boiling water)
Car runs great but temps consistently climb past 220 with ease. Am I missing something?
Race Director
Joined: Mar 2017
Posts: 11,929
Likes: 4,497
From: Virginia
Have you pressure tested your radiator cap? Checked for a spring in your lower radiator hose?
79 has an optional lip spoiler that only a few cars got. If you are overheating at speed, and the rest of your foam is intact, this might help.
https://www.ecklerscorvette.com/1979...-314844-1.html
Finally, have you checked for a head gasket leak (either by running without the cap, or testing for exhaust gases)?
79 has an optional lip spoiler that only a few cars got. If you are overheating at speed, and the rest of your foam is intact, this might help.
https://www.ecklerscorvette.com/1979...-314844-1.html
Finally, have you checked for a head gasket leak (either by running without the cap, or testing for exhaust gases)?
Thread Starter
Intermediate
Joined: Aug 2017
Posts: 33
Likes: 4
From: South Florida
Thread Starter
Intermediate
Joined: Aug 2017
Posts: 33
Likes: 4
From: South Florida
Have you pressure tested your radiator cap? Checked for a spring in your lower radiator hose?
79 has an optional lip spoiler that only a few cars got. If you are overheating at speed, and the rest of your foam is intact, this might help.
https://www.ecklerscorvette.com/1979...-314844-1.html
Finally, have you checked for a head gasket leak (either by running without the cap, or testing for exhaust gases)?
79 has an optional lip spoiler that only a few cars got. If you are overheating at speed, and the rest of your foam is intact, this might help.
https://www.ecklerscorvette.com/1979...-314844-1.html
Finally, have you checked for a head gasket leak (either by running without the cap, or testing for exhaust gases)?
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,169
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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Having a spoiler/ splitter, a sealed airbox in front of the radiator and all the radiator seals are key to keeping it cool...then its flushing it and making sure the fans are running in the right direction...if they are on the inside and you installed pushers it ain't gonna work....if it overheats at speed that's because of an airflow problem, if its in stop and go traffic it's a bad fan combination, non working fan and or a shroud issue, the fans all need a shroud that seals against the radiator but allows airflow at speed
If all that works pull your thermostat and see if it goes away...ive had sticking stats before
If all that works pull your thermostat and see if it goes away...ive had sticking stats before
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Melting Slicks
Joined: Jul 2006
Posts: 2,286
Likes: 487
From: Salmon Arm, BC
I agree with the others about the seals are a must have.....although I'm missing the top one on mine and have no cooling issues....I'm running a small block....540 cubes are a bit different 
Pic of shroud and fans would be helpful. Many times it's the shroud that's the problem... either it's not big enough and encompassing the whole rad, or the shroud is to close to the fins and it doesn't allow free flow of air through the whole rad. There was a recent thread on this very issue.
Keep us posted...
Pic of shroud and fans would be helpful. Many times it's the shroud that's the problem... either it's not big enough and encompassing the whole rad, or the shroud is to close to the fins and it doesn't allow free flow of air through the whole rad. There was a recent thread on this very issue.
Keep us posted...
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From: Sunshine Coast, Queensland, Australia
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Cruise-In VIII Veteran
I goggled the brand of fan the OP mentions he has. Most have no shroud, some have a flat pan style shroud. I had tryed one of those once. Terrible air flow.
Get some C5 Corvette fans. A little bit of trimming and they fit up beautifully. And the built in factory style shroud really works.
You simply can't beat the OEM stuff. CFM numbers can sound impressive, but it's the design of the shroud that actually moves the air. And in the correct way both with fans running and not.
Get some C5 Corvette fans. A little bit of trimming and they fit up beautifully. And the built in factory style shroud really works.
You simply can't beat the OEM stuff. CFM numbers can sound impressive, but it's the design of the shroud that actually moves the air. And in the correct way both with fans running and not.
Thread Starter
Intermediate
Joined: Aug 2017
Posts: 33
Likes: 4
From: South Florida
Alright so I have a 1979 corvette with a BBC 540 and I can’t get the thing to run cool.
I have a 4 core champion radiator running a 80/20 mix with water wetter added to it.
Dual maradyne electric fans with shroud about 3500cfm
Stewart stage 2 aluminum water pump with a march under drive pulley.
Timing is set at 18 initial with mechanical advance all the way to 38 at 3000rpm
165 thermostat that is operational and doesn’t stick(confirmed in boiling water)
Car runs great but temps consistently climb past 220 with ease. Am I missing something?
I have a 4 core champion radiator running a 80/20 mix with water wetter added to it.
Dual maradyne electric fans with shroud about 3500cfm
Stewart stage 2 aluminum water pump with a march under drive pulley.
Timing is set at 18 initial with mechanical advance all the way to 38 at 3000rpm
165 thermostat that is operational and doesn’t stick(confirmed in boiling water)
Car runs great but temps consistently climb past 220 with ease. Am I missing something?
