Cooling issue
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Simplified terms;
The engine is creating too much heat for the cooling system.
I.E., Retarded timing, too lean, improper lubrication. (Friction).
The cooling system cannot handle the heat generated. I.E.,
Wrong pump, stat, fan, radiator,coolant,blockage, etc.
It CAN be both, but usually one or the other. 3 miles is is too quick. 200* is expected with that stat. 235* is the cusp of damage.
If I lived close, I'd shoot over and find it in a day.
The engine is creating too much heat for the cooling system.
I.E., Retarded timing, too lean, improper lubrication. (Friction).
The cooling system cannot handle the heat generated. I.E.,
Wrong pump, stat, fan, radiator,coolant,blockage, etc.
It CAN be both, but usually one or the other. 3 miles is is too quick. 200* is expected with that stat. 235* is the cusp of damage.
If I lived close, I'd shoot over and find it in a day.
Last edited by Big2Bird; Jan 20, 2019 at 09:04 PM.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Too much heat
Simplified terms;
The engine is creating too much heat for the cooling system.
I.E., Retarded timing, too lean, improper lubrication. (Friction).
The cooling system cannot handle the heat generated. I.E.,
Wrong pump, stat, fan, radiator,coolant,blockage, etc.
It CAN be both, but usually one or the other. 3 miles is is too quick. 200* is expected with that stat. 235* is the cusp of damage.
If I lived close, I'd shoot over and find it in a day.
The engine is creating too much heat for the cooling system.
I.E., Retarded timing, too lean, improper lubrication. (Friction).
The cooling system cannot handle the heat generated. I.E.,
Wrong pump, stat, fan, radiator,coolant,blockage, etc.
It CAN be both, but usually one or the other. 3 miles is is too quick. 200* is expected with that stat. 235* is the cusp of damage.
If I lived close, I'd shoot over and find it in a day.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Hell the way it’s going I’m about to buy you a plane ticket. I did get him to admit he bought the radiator for a 78 Vet with no consideration for the 383. I told him those engines had less than 200 hp off the production line and he was very quiet. Said the fans are just universal fit 12” fans. I’m going to look at the invoices tomorrow and check into radiator solutions. I’m bleeding money on these guys and I need to see an end solution. Thanks again.
A ticket would be enticing, but there are lots of members close to you that can do this.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
It is really hard to troubleshoot cooling issues on the forum because you have many ideas and suggestions coming in from all directions. Some are good ones and some are very misleading. Usually the "oneline" solutions are not the answer but rather something that work for them with something completely different than what you have. I typically ask a dozen questions before making any recommendation and I have many times "unsold" a new aluminum radiator by finding an issue with timing, sending unit, or some other issue. I am retired now and I do not PM, but I would suggest you call DeWitts and talk with John. He can help diagnose the problem.
There are two types of fan systems, #1 the stock system with a shroud, fan clutch, and engine driven fan. With this system a shroud and seals are a must. #2 is the electric fans and here you do not need a shroud or seals if it is designed correctly. The basic starting point is 2000 cfm of air flow and 70% core coverage. Not sure you have that.
I see you have a serpentine belt system and that can cause a couple issues. The water pump runs backwards rotation and sometimes they have smaller pulley that overdrives the pump. Too much flow can be a problem. 235 degrees in three miles is more than a seal or drilling holes in a stat.
You may or may not need a new system, but if I was asked to suggest a unit (with electric fans) I would use :
Model: 4139077A (Natural/Auto)
Webpage
There are two types of fan systems, #1 the stock system with a shroud, fan clutch, and engine driven fan. With this system a shroud and seals are a must. #2 is the electric fans and here you do not need a shroud or seals if it is designed correctly. The basic starting point is 2000 cfm of air flow and 70% core coverage. Not sure you have that.
I see you have a serpentine belt system and that can cause a couple issues. The water pump runs backwards rotation and sometimes they have smaller pulley that overdrives the pump. Too much flow can be a problem. 235 degrees in three miles is more than a seal or drilling holes in a stat.
You may or may not need a new system, but if I was asked to suggest a unit (with electric fans) I would use :
Model: 4139077A (Natural/Auto)
Webpage
Last edited by Tom@Dewitt; Jan 20, 2019 at 09:41 PM. Reason: Added Link
Le Mans Master
Joined: Jan 2001
Posts: 6,713
Likes: 1,372
Your radiator looks fine. There is nothing super special about your setup. You don't need to be buying a bunch of stuff like a radiator or fans yet. I suggest you stop throwing money at it and go through the suggested checks.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
It is really hard to troubleshoot cooling issues on the forum because you have many ideas and suggestions coming in from all directions. Some are good ones and some are very misleading. Usually the "oneline" solutions are not the answer but rather something that work for them with something completely different than what you have. I typically ask a dozen questions before making any recommendation and I have many times "unsold" a new aluminum radiator by finding an issue with timing, sending unit, or some other issue. I am retired now and I do not PM, but I would suggest you call DeWitts and talk with John. He can help diagnose the problem.
There are two types of fan systems, #1 the stock system with a shroud, fan clutch, and engine driven fan. With this system a shroud and seals are a must. #2 is the electric fans and here you do not need a shroud or seals if it is designed correctly. The basic starting point is 2000 cfm of air flow and 70% core coverage. Not sure you have that.
I see you have a serpentine belt system and that can cause a couple issues. The water pump runs backwards rotation and sometimes they have smaller pulley that overdrives the pump. Too much flow can be a problem. 235 degrees in three miles is more than a seal or drilling holes in a stat.
You may or may not need a new system, but if I was asked to suggest a unit (with electric fans) I would use :
Model: 4139077A (Natural/Auto)
Webpage
There are two types of fan systems, #1 the stock system with a shroud, fan clutch, and engine driven fan. With this system a shroud and seals are a must. #2 is the electric fans and here you do not need a shroud or seals if it is designed correctly. The basic starting point is 2000 cfm of air flow and 70% core coverage. Not sure you have that.
I see you have a serpentine belt system and that can cause a couple issues. The water pump runs backwards rotation and sometimes they have smaller pulley that overdrives the pump. Too much flow can be a problem. 235 degrees in three miles is more than a seal or drilling holes in a stat.
You may or may not need a new system, but if I was asked to suggest a unit (with electric fans) I would use :
Model: 4139077A (Natural/Auto)
Webpage
Tom. Thank you for your response. I’m going to locate some invoices and check on the water pump today. After that, I’ll call John.
I appreciate all the help everyone has volunteered on this site.
Regards. Dianne
PS. Penelope is my 78 ��
I appreciate all the help everyone has volunteered on this site.
Regards. Dianne
PS. Penelope is my 78 ��
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Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
See if there are any part numbers on that water pump.
Your radiator looks fine. There is nothing super special about your setup. You don't need to be buying a bunch of stuff like a radiator or fans yet. I suggest you stop throwing money at it and go through the suggested checks.
Your radiator looks fine. There is nothing super special about your setup. You don't need to be buying a bunch of stuff like a radiator or fans yet. I suggest you stop throwing money at it and go through the suggested checks.
I’m going to track down the water pump today if I can. I’ll post back what I find. Thank you
Race Director
Joined: Jun 2000
Posts: 10,039
Likes: 670
From: FL
Couple of more thoughts.
1) Took a look at your photos. Visually, the water pump looks like the Edelbrock reverse rotation for small block chevy.
2) Most aftermarket serpentine systems are setup with a “performance” ratio that actually slows down the water pump to reduce horsepower loss. I have March serpentine on my big block and had to get a larger crank pulley to speed up the water pump. That, in conjunction with the big spoiler helped cure low speed cooling for my 496 big block.
3) The seals are absolutely critical to getting all the air to flow through your radiator.
1) Took a look at your photos. Visually, the water pump looks like the Edelbrock reverse rotation for small block chevy.
2) Most aftermarket serpentine systems are setup with a “performance” ratio that actually slows down the water pump to reduce horsepower loss. I have March serpentine on my big block and had to get a larger crank pulley to speed up the water pump. That, in conjunction with the big spoiler helped cure low speed cooling for my 496 big block.
3) The seals are absolutely critical to getting all the air to flow through your radiator.
Last edited by SteveG75; Jan 22, 2019 at 04:33 PM.
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
Random thoughts....
1. It seems as if the radiator support is very far from the radiator. The gap is huge. Even without seals. Is there a radiator/support/bracket mismatch?
2. Lower hose. Why the universal fit hose? A Corvette hose with the internal support spring should hook up no problem...if the radiator has the proper outlet configuration. is there a sroing inside the lower hose.
3. Squeeze the upper and lower hoses when its running.. If the water pump is spinning backwards the lower hose will be very hard.
Fix know mechanical issues first. Radiator to shroud sealing? lower hose? Correct direction water pump etc. Pick a starting point and follow the system to locate any trouble spots. Ex. start at the thermostat housing... correct housing? Correct-stat? correct upper hose? Radiator full of fluid? Correct cap? Correct lower hose.? Correct water pump? Heater hoses oriented correctly?
1. It seems as if the radiator support is very far from the radiator. The gap is huge. Even without seals. Is there a radiator/support/bracket mismatch?
2. Lower hose. Why the universal fit hose? A Corvette hose with the internal support spring should hook up no problem...if the radiator has the proper outlet configuration. is there a sroing inside the lower hose.
3. Squeeze the upper and lower hoses when its running.. If the water pump is spinning backwards the lower hose will be very hard.
Fix know mechanical issues first. Radiator to shroud sealing? lower hose? Correct direction water pump etc. Pick a starting point and follow the system to locate any trouble spots. Ex. start at the thermostat housing... correct housing? Correct-stat? correct upper hose? Radiator full of fluid? Correct cap? Correct lower hose.? Correct water pump? Heater hoses oriented correctly?
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Hello folks
i called March and with the help of Price he confirmed they sent the reverse rotation water pump with my kit parts. I told him about the overheating and he suggested thermostat much lower like 160 which several of you have mentioned and might check whether the water is moving too fast. He said to look for Morosso resistors to slow it down. I think I saw this comment elsewhere. So waiting on parts and ready to ride.
i called March and with the help of Price he confirmed they sent the reverse rotation water pump with my kit parts. I told him about the overheating and he suggested thermostat much lower like 160 which several of you have mentioned and might check whether the water is moving too fast. He said to look for Morosso resistors to slow it down. I think I saw this comment elsewhere. So waiting on parts and ready to ride.
Race Director
Joined: Apr 2003
Posts: 19,347
Likes: 654
From: Tampa, Florida
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
No big deal on suction side of fuel pump. If it leaks between the pump and carb, you will get gallons of fuel on top of a hot engine/manifold in seconds.
Dianne, splitting all this into an old and new thread is killing me. Pick one.
Dianne, splitting all this into an old and new thread is killing me. Pick one.
Last edited by Big2Bird; Jan 21, 2019 at 05:57 PM.
Advanced
Joined: Jan 2019
Posts: 63
Likes: 2
From: SE Florida
Couple of more thoughts.
1) Took a look at your photos. Visually, the water pump looks like the Edelbrock reverse flow for small block chevy.
2) Most aftermarket serpentine systems are setup with a “performance” ratio that actually slows down the water pump to reduce horsepower loss. I have March serpentine on my big block and had to get a larger crank pulley to speed up the water pump. That, in conjunction with the big spoiler helped cure low speed cooling for my 496 big block.
3) The seals are absolutely critical to getting all the air to flow through your radiator.
1) Took a look at your photos. Visually, the water pump looks like the Edelbrock reverse flow for small block chevy.
2) Most aftermarket serpentine systems are setup with a “performance” ratio that actually slows down the water pump to reduce horsepower loss. I have March serpentine on my big block and had to get a larger crank pulley to speed up the water pump. That, in conjunction with the big spoiler helped cure low speed cooling for my 496 big block.
3) The seals are absolutely critical to getting all the air to flow through your radiator.
Hi. Called March and I’ve got the right water pump. Seals on order along with a shroud. Will post an update when parts roll in and get installed probably first next week. Thanks
Former Vendor
Joined: Jan 2000
Posts: 5,593
Likes: 631
From: Brighton
I think you are wasting your time and money. A shrouds' only function is to duct the air up to an engine driven fan. You don't have one!
I don't mean to blow my own horn but solving Corvette cooling issues is all I have done for the last twenty years. Nobody can match the number of clients I have worked with on this issue. Why someone would consult a carpenter, truck driver, and school teacher about a surgical procedure is a mystery to me.
Q: Did anyone ever confirm your gauge reading with an IR gun?
Many replacement temperature sending units are not correct and read much higher than the actual temperature. Many times people claim they are running hot when they are not because they assumed the gauge was correct. Most of them do not find this out until they spent a whole bunch of money trying to solve a problem they don't have.
I don't mean to blow my own horn but solving Corvette cooling issues is all I have done for the last twenty years. Nobody can match the number of clients I have worked with on this issue. Why someone would consult a carpenter, truck driver, and school teacher about a surgical procedure is a mystery to me.
Q: Did anyone ever confirm your gauge reading with an IR gun?
Many replacement temperature sending units are not correct and read much higher than the actual temperature. Many times people claim they are running hot when they are not because they assumed the gauge was correct. Most of them do not find this out until they spent a whole bunch of money trying to solve a problem they don't have.
Last edited by Tom@Dewitt; Jan 21, 2019 at 07:30 PM.