Cooling issue
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
As stated by a couple of other members in this thread....I cannot stress the importance of correct timing on overall engine performance which includes cooling. I would hope your mechanic would start here. The reason you SHOULD start here is because for one thing it is free/cheap.....the other is once it is right, then you can go determine if chasing fans and radiators will be beneficial. A good mechanic would go here first and if your mechanic scoffs at it, find another. Also, if the mechanics claims to be able to set timing by ear, lose his/her number.
After timing is set, have them perform the idle screw adjustment just for the hell of it. The two go hand in hand.
Do you have any pics of the engine compartment?
Good luck to you and post your results!
Jebby
After timing is set, have them perform the idle screw adjustment just for the hell of it. The two go hand in hand.
Do you have any pics of the engine compartment?
Good luck to you and post your results!
Jebby
Race Director
Joined: Mar 2016
Posts: 14,327
Likes: 8,130
From: Napa Valley California
After you check the timing and other things mentioned in this thread, I would check to see if you could find documentation on the water pump, fans and the radiator itself.
Post what you can find and we can go from there.
Do you know the age, material or anything else regarding the radiator?
Post what you can find and we can go from there.
Do you know the age, material or anything else regarding the radiator?
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
first you need to install the core support seals and radiator seals, most of the air while driving is bypassing the radiator and passing over the top of the core support and around the radiator. While sitting the air is circulating from the engine bay back over the top of the radiator and back through the radiator (hot air).
You need the seals,
Neal
You need the seals,
Neal
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Shroud
If the fans are mounted to the rad and you have open areas on the rad I had the same issue. Stock system requires ALL foam to seal air leaks in place.
I now run a dewitts aluminum rad but the ticket was their shroud that includes 2 fans. No dead areas as it draws over the entire rad.
I now run a dewitts aluminum rad but the ticket was their shroud that includes 2 fans. No dead areas as it draws over the entire rad.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Radiator
After you check the timing and other things mentioned in this thread, I would check to see if you could find documentation on the water pump, fans and the radiator itself.
Post what you can find and we can go from there.
Do you know the age, material or anything else regarding the radiator?
Post what you can find and we can go from there.
Do you know the age, material or anything else regarding the radiator?
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Seals
first you need to install the core support seals and radiator seals, most of the air while driving is bypassing the radiator and passing over the top of the core support and around the radiator. While sitting the air is circulating from the engine bay back over the top of the radiator and back through the radiator (hot air).
You need the seals,
Neal
You need the seals,
Neal
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
"Positive that is the right water pump"? That's b.s. Tell him to verify that. If it's a regular rotation water pump and he's spinning in reverse rotation with that serpentine setup, then you're going to have the exact same problems you're describing.
Radiator is new along with fans. I’ve talked with my mechanics and very strongly reminded them this is not the typical Chevy they work on. This is American muscle and has special needs. I sent them comments from the forum to and I think we are on the same page. We’re looking for a shroud for the fans. Mechanic assured me he is positive that is the right water pump. I’ll force the issues if I have to. I’ve managed $10million projects so I’m not threatened by a couple of guys spending my money. Any rate I could not have done this without all you guys on this forum so many thanks.
Radiator is new along with fans. I’ve talked with my mechanics and very strongly reminded them this is not the typical Chevy they work on. This is American muscle and has special needs. I sent them comments from the forum to and I think we are on the same page. We’re looking for a shroud for the fans. Mechanic assured me he is positive that is the right water pump. I’ll force the issues if I have to. I’ve managed $10million projects so I’m not threatened by a couple of guys spending my money. Any rate I could not have done this without all you guys on this forum so many thanks.
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
A statement below stood out.... If you are going to some mechanic that only works on the newer computer controlled systems, then they might have a tough ascertaining the issues with your older SBC system. This is not terribly difficult to troubleshoot, so if these guys cannot figure it out promptly, then you may wish to take your car elsewhere.
Radiator is new along with fans. I’ve talked with my mechanics and very strongly reminded them this is not the typical Chevy they work on. This is American muscle and has special needs. I sent them comments from the forum to and I think we are on the same page. We’re looking for a shroud for the fans. Mechanic assured me he is positive that is the right water pump. I’ll force the issues if I have to. I’ve managed $10million projects so I’m not threatened by a couple of guys spending my money. Any rate I could not have done this without all you guys on this forum so many thanks.
Radiator is new along with fans. I’ve talked with my mechanics and very strongly reminded them this is not the typical Chevy they work on. This is American muscle and has special needs. I sent them comments from the forum to and I think we are on the same page. We’re looking for a shroud for the fans. Mechanic assured me he is positive that is the right water pump. I’ll force the issues if I have to. I’ve managed $10million projects so I’m not threatened by a couple of guys spending my money. Any rate I could not have done this without all you guys on this forum so many thanks.
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
A statement below stood out.... If you are going to some mechanic that only works on the newer computer controlled systems, then they might have a tough ascertaining the issues with your older SBC system. This is not terribly difficult to troubleshoot, so if these guys cannot figure it out promptly, then you may wish to take your car elsewhere.
I also see that her location is Florida as well. I took my thermostat out years ago for better flow, not really needed here in Florida, it's plenty hot here.
Last edited by Doug1; Jan 18, 2019 at 07:10 AM.
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
https://www.corvettecentral.com/search?CurrentSearchCategoryId=&q=radiat or+seal&Years=1978
You can get generic brand foam from Home Depot and make seals also.
Last edited by Street Rat; Jan 18, 2019 at 09:39 AM.
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
Here are the seal kits that were offered for the '78...
https://www.corvettecentral.com/search?CurrentSearchCategoryId=&q=radiat or+seal&Years=1978
You can get generic brand foam from Home Depot and make seals also.
https://www.corvettecentral.com/search?CurrentSearchCategoryId=&q=radiat or+seal&Years=1978
You can get generic brand foam from Home Depot and make seals also.
That's what I have with my Summit Radiator and Mark 8 Fan. If nothing else just for you to check it is making a difference. You can always exchange them later if it matters to you.
Last edited by carriljc; Jan 18, 2019 at 10:21 AM.
Melting Slicks
Joined: May 2002
Posts: 2,716
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
https://willcoxcorvette.com/corvette...itioning-78-78
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
Last edited by chevymans 77; Jan 18, 2019 at 10:21 AM.
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
Last edited by carriljc; Jan 20, 2019 at 03:55 PM.
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
https://willcoxcorvette.com/corvette...itioning-78-78
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
Great looking engine btw penelope.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
Great looking engine btw penelope.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
This is a good thread.
Great looking engine btw Penelope.
Last edited by Doug1; Jan 18, 2019 at 04:24 PM.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Setup?
Im trying to gather as much info as I can. What setup are you using for shroud/fans? Recommendations? I ordered an aluminum shroud but I’m worried if my fans have enough cfm . Thanks
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Seals
https://willcoxcorvette.com/corvette...itioning-78-78
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
https://willcoxcorvette.com/corvette...ning-76l-76-78
Depending on your cars options,
The gap over the radiator and between the hood has to be sealed so air will be forced through the radiator and condenser. Air will take the path of least resistance, around the radiator. Also there are gaps on the sides of the radiator at the core support that need to be sealed, the idea is to make all the air pass through the radiator.
This may not cure all your cooling issues but it is the first item that needs to be fixed, wont know until this is taken care of.
Neal
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Rad?
If the fans are mounted to the rad and you have open areas on the rad I had the same issue. Stock system requires ALL foam to seal air leaks in place.
I now run a dewitts aluminum rad but the ticket was their shroud that includes 2 fans. No dead areas as it draws over the entire rad.
I now run a dewitts aluminum rad but the ticket was their shroud that includes 2 fans. No dead areas as it draws over the entire rad.
Safety Car
Joined: Sep 2012
Posts: 4,688
Likes: 41
From: Palm Harbor, Florida
Well Penelope you've had a lot of ideas thrown at you. Get the shroud and existing fans installed and see what happens. That's my advice.
I don't have a shroud for my fans, but I also don't have any of my ac parts, the condensor sits in front of radiator and hinders air flow. Since I don't have that, my car does ok with temp. Since you have ac, the shroud is gonna get you that air flow that is probably lacking.
I don't have a shroud for my fans, but I also don't have any of my ac parts, the condensor sits in front of radiator and hinders air flow. Since I don't have that, my car does ok with temp. Since you have ac, the shroud is gonna get you that air flow that is probably lacking.
Last edited by Doug1; Jan 20, 2019 at 10:16 AM.