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The front runner system is suppused to come with a water pump, so it should be correct....freeway overheating is usually air restriction or undersized radiator. Have you tried no thermostat at all at least that's cheap. There were a lot of british cars that had undersized grill openings, they wouldn't get hot in overcast England but the southwestern US is another story.
 

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Discussion Starter #42
The owner is out of town so the car is in jail right now. Will try to get pictures when he gets back in a week or so. He drove it by here a week or so ago. It's not a project that gets worked on 24/7 but I would like to figure something out before first of October because of his upcoming trip to Cruising the Coast. The car has a Stewarts 185 thermostat in it now but he has put several different brands and temperatures just to see if it would make a difference. I talked to him about pulling the thermostat out and seeing if it would make a difference. He has flushed it a couple of times and has gotten a lot of debris. I'm hoping some of the cooling tubes are stopped up. If that's the case the new radiator should fix it. I also think like Mike Goble about getting water through the radiator. I have a good friend who believes the opposite. He thinks you need to slow water intake into the radiator to give it more time in the radiator making it cool better. I know the newer cars run hotter than we used to be comfortable with. Even with aluminum heads I don't think 220 will hurt anything but it makes me uneasy. I don't want my older engines over 210 if I can help it. I'm 54 years old and I guess I'm just old school
 

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I also think like Mike Goble about getting water through the radiator. I have a good friend who believes the opposite. He thinks you need to slow water intake into the radiator to give it more time in the radiator making it cool better.
Ask your friend how the thermostat controls the temperature. When it's closed and restricting the flow and the engine warms up. When it's open and allowing increased flow, the temperature goes down.
 

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Discussion Starter #44
Ask your friend how the thermostat controls the temperature. When it's closed and restricting the flow and the engine warms up. When it's open and allowing increased flow, the temperature goes down.
Sometimes it's just better to let sleeping dogs lie. We have hashed it around for years. It's to the point that he's not going to change my mind and I'm not going to change his. I can understand his argument I just don't believe it. I think the quicker you can get hot water to the place it starts cooling the better it will cool within reason.
 

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I have a friend with a 1967 Chevelle that has a mild 396 big block in it. It has a champion aluminum radiator in it with two electric fans on it. I have checked to make sure the fans are turning the right way. While the car is going down the road it is wanting to heat up. He usually stops it when it gets in the 215 area. If he stops the car and lets it idle it will cool back down. It has a Vintage air front runner system on it with I'm sure a stewart water pump. The water pump seems to be circulating the water in the radiator fine. I would think the car should be getting plenty enough air going down the road to cool it. It has two gauges on it. A Dakota Digital and a Sniper coolant temp sensor. Both gauges are reading pretty close so I don't think it a gauge issue. My friend has tried several thermostats and flushed the radiator out using several different brands of radiator flush. I've been around cars all my life and what I'm seeing simply doesn't make sense. Most of the time if a car is heating up going down the road it is a air flow issue. On my 1965 Nova I can take the relay's out of my fans and it won't heat up driving at highway speeds. I've actually seen him drive up with the car running close to 220 and let it idle in my driveway until it cools enough to start cycling the fans off and on. At this point I'm thinking it must be a radiator or water pump issue but just looking at them they seem to be fine. It isn't losing water to make me think it's a engine problem and I set the timing myself so I know it's right. Anybody want to venture a guess. Mike Goble?
I have a friend with a 1967 Chevelle that has a mild 396 big block in it. It has a champion aluminum radiator in it with two electric fans on it. I have checked to make sure the fans are turning the right way. While the car is going down the road it is wanting to heat up. He usually stops it when it gets in the 215 area. If he stops the car and lets it idle it will cool back down. It has a Vintage air front runner system on it with I'm sure a stewart water pump. The water pump seems to be circulating the water in the radiator fine. I would think the car should be getting plenty enough air going down the road to cool it. It has two gauges on it. A Dakota Digital and a Sniper coolant temp sensor. Both gauges are reading pretty close so I don't think it a gauge issue. My friend has tried several thermostats and flushed the radiator out using several different brands of radiator flush. I've been around cars all my life and what I'm seeing simply doesn't make sense. Most of the time if a car is heating up going down the road it is a air flow issue. On my 1965 Nova I can take the relay's out of my fans and it won't heat up driving at highway speeds. I've actually seen him drive up with the car running close to 220 and let it idle in my driveway until it cools enough to start cycling the fans off and on. At this point I'm thinking it must be a radiator or water pump issue but just looking at them they seem to be fine. It isn't losing water to make me think it's a engine problem and I set the timing myself so I know it's right. Anybody want to venture a guess. Mike Goble?
You have not mentioned anything regarding the electric fans coming on while on the road with increasing water temp. I would suggest you have an air flow or radiator obstruction issue. I would bypass fan thermostat and run fans continuously while driving and see if any changes occur.
 

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Sometimes it's just better to let sleeping dogs lie. We have hashed it around for years. It's to the point that he's not going to change my mind and I'm not going to change his. I can understand his argument I just don't believe it. I think the quicker you can get hot water to the place it starts cooling the better it will cool within reason.
The fundamental flawed assumption that some folks make is that the radiator is a water cooler, and that it needs to cool the water in order to cool the engine. It is actually a heat dissipator, and the more heat it dissipates the cooler the engine will run. The radiator dissipates heat by being as hot as you can get it across its entirety, as the reduction in temperature from inlet to outlet reduces the efficiency.
This is exactly what happens as the thermostat closes down and restricts the flow of coolant through the radiator, increasing the temperature drop from inlet to outlet. The efficiency of the radiator is reduced in order to keep the engine warm.
If the coolant temperature rises and signals the thermostat to open, the temperature difference across the radiator will decrease as the outlet becomes warmer. Because the radiator as a whole is warmer, it dissipates more heat from the engine.
 

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Discussion Starter #47 (Edited)
You have not mentioned anything regarding the electric fans coming on while on the road with increasing water temp. I would suggest you have an air flow or radiator obstruction issue. I would bypass fan thermostat and run fans continuously while driving and see if any changes occur.
Any time the water temperature gets to a certain point the fans turn on. While the car is going down the road after it reaches that point the fans are running. The way it is configured both fans come on wide open. There is no one fan coming on at one temperature and the other coming on at another. When one comes on both come on and they are blowing wide open when they come on. I also believe it is a airflow or obstruction issue. The only thing is I'm having a hard time trying to figure out is how it could be air flow going down the road. The car design in question isn't known to have cooling issues such as the 1st and 2nd gen Novas. Going down the road it should catch more than enough air to cool. It isn't having to cool massive amounts of horsepower. I would guesstimate maybe 300. That brings me back to believing it is a obstruction and there has been a lot of debris when flushing the radiator. Going by my car, which is a 1965 Nova with probably 450 hp, I can pull my fan relays going down the road and the car will still cool. I have seen the car run hot going down the road with both fans running and you can stop the car and in a few minutes it will cool enough to turn the fans off. After it reaches that point it will sit as long as you want cycling the fans off and on to keep it at or very near 185 degrees. It has a 185 thermostat in it. The guys just got back from their trip so if the new radiator is in we should know in a few days if that really is the problem. Since I'm not sure what else it could be I'm keeping my fingers crossed.
 

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If I have a 500 hp motor in my Nova and you have a 300 hp motor in your very similar Nova and we are driving side-by-side at 60 mph down the freeway, which engine is making the most power and why?
 

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I have a 800 hp 871 blown sbc in my 66 and have dealt with the temp issue for quite a while, trying many things until I finally got it dialed in. I run dual 12" fans with an aluminum shroud I made. The fans are controlled by the temp at the thermostat housing, each on a separate set point. When I am running down the road both fans will go off, no need for them to be running if not needed. I also have vent flaps to allow an air bypass of the fans in the shroud when driving down the road. In the pic you can see the flaps, above and below the fans, behind each are a row of 2" holes. The air flow will open the flaps for more airflow, when the airflow is low the flaps will close to make sure all airflow from the fans comes through the radiator.
409620

I have had to make quite a few adjustments to the timing curve at certain rpm points to keep the temp under control, my timing is controlled in 500 rpm increments over the entire curve so I can dial in each point independently and the controller will interpolate between them, even from the dash while driving. Just remember that the timing curve is more than just the low point and the high point, it is also important where it is at certain rpms.
 

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I forgot to mention that I did an experiment with the flaps also to prove to myself they were working as planned. I went out for a drive with the flaps functioning and recorded the temps, then secured them so they wouldn't open and went out on the same drive again, the flaps DO work as intended !
 

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Discussion Starter #52
If I have a 500 hp motor in my Nova and you have a 300 hp motor in your very similar Nova and we are driving side-by-side at 60 mph down the freeway, which engine is making the most power and why?
I'm almost afraid to answer. I'm afraid I might fail the test but here goes. It would depend on the gearing/tire combination (as well as other items also) because engines make power and torque in curves. If one engine is up a little in RPM or in the sweet spot rpm wise it could be making more HP at 60 mph than a engine with a lot more peak hp. The engine making less hp overall very well could be making more hp down low in the power curve. Peak hp numbers do not always mean high hp numbers down low so my answer is (crossing my fingers) it depends on the combination overall. Also, we all talk about hp but in reality torque is just as important.
 

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The fundamental flawed assumption that some folks make is that the radiator is a water cooler, and that it needs to cool the water in order to cool the engine. It is actually a heat dissipator, and the more heat it dissipates the cooler the engine will run. The radiator dissipates heat by being as hot as you can get it across its entirety, as the reduction in temperature from inlet to outlet reduces the efficiency.
This is exactly what happens as the thermostat closes down and restricts the flow of coolant through the radiator, increasing the temperature drop from inlet to outlet. The efficiency of the radiator is reduced in order to keep the engine warm.
If the coolant temperature rises and signals the thermostat to open, the temperature difference across the radiator will decrease as the outlet becomes warmer. Because the radiator as a whole is warmer, it dissipates more heat from the engine.
Engine Heat / Coolant issues give me the headache. I would agree that the radiator dissipates heat. So airflow by driving and pulling of fan (mechanical or electrical) aids in the dissipation. So consequently is the water not also being "cooled" in the radiator? Not splitting hairs but anyway you can reduce the heat in the coolant, the cooler the engine should run. I'm following this thread because I don't understand HOW the car runs Hot going down the road but not while idling.
 

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Shane65 spotted a potential problem in the missing bypass hose from the front of the intake manifold to the top of the water pump. Not sure how the B block system works but it would definitely restrict flow. Good Luck
 

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I'm almost afraid to answer. I'm afraid I might fail the test but here goes. It would depend on the gearing/tire combination (as well as other items also) because engines make power and torque in curves. If one engine is up a little in RPM or in the sweet spot rpm wise it could be making more HP at 60 mph than a engine with a lot more peak hp. The engine making less hp overall very well could be making more hp down low in the power curve. Peak hp numbers do not always mean high hp numbers down low so my answer is (crossing my fingers) it depends on the combination overall. Also, we all talk about hp but in reality torque is just as important.
Very similar means same gearing, tire size, weight, drag coefficient, etc. The only difference in these Novas is the HP rating of the motor. We are driving side-by-side in the same gear at the same rpm.
 

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Very similar means same gearing, tire size, weight, drag coefficient, etc. The only difference in these Novas is the HP rating of the motor. We are driving side-by-side in the same gear at the same rpm.
same amount of horsepower for both cars🤓
 

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If I have a 500 hp motor in my Nova and you have a 300 hp motor in your very similar Nova and we are driving side-by-side at 60 mph down the freeway, which engine is making the most power and why?
same amount of horsepower for both cars🤓
I was thinking the same thing.... each engine will be making the same amount of HP since I imagine it takes the same amount of energy to move similar vehicles at the same speed.
 

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Engine Heat / Coolant issues give me the headache. I would agree that the radiator dissipates heat. So airflow by driving and pulling of fan (mechanical or electrical) aids in the dissipation. So consequently is the water not also being "cooled" in the radiator? Not splitting hairs but anyway you can reduce the heat in the coolant, the cooler the engine should run. I'm following this thread because I don't understand HOW the car runs Hot going down the road but not while idling.
Dissipating heat doesn't depend on reducing the heat of the coolant, in fact, less heat is dissipated by lower temperature coolant. For any given amount of heat produced by the engine, there is an average radiator temperature that will dissipate that amount of heat. For low levels of power, a lower average radiator temperature is sufficient. You achieve this by restricting the flow and allowing the coolant to lose temperature in the radiator. Your thermostat controls the inlet temperature, and the flow sets the outlet temperature. For example, if the inlet is 180° and the outlet is 100°, the average temperature is 140°, halfway between the inlet and outlet temperatures. Let's say we come to a hill and maintain the same speed, thus producing more heat in the engine. The thermostat will sense this increase and open an amount necessary to increase the flow. Since the flow has increased, the outlet of the radiator will become warmer, raising the average temperature. Let's say that the outlet temperature rises from 100° to 140°. The average radiator temperature is now 160°, and the radiator is dissipating more heat.

The most heat is dissipated when you can get the highest average radiator temperature, done by pumping as much coolant as possible through the radiator. There are limits to how much you can pump based on the restrictions in the system and the type of pump.

Here's some reading on the effects of flow in the system.

 

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Discussion Starter #59
Very similar means same gearing, tire size, weight, drag coefficient, etc. The only difference in these Novas is the HP rating of the motor. We are driving side-by-side in the same gear at the same rpm.
I would think they would be making about the same if everything was similar. It takes a certain HP to move identical cars the same mph.

I'm following this thread because I don't understand HOW the car runs Hot going down the road but not while idling.
I don't understand it either and I'm trying to help the guy fix it. It's hard to fix something when you don't know what's wrong with it.
 

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Tool idea? May help?
Using Mike's post information & link explaining temperature differentials (great info), using a infrared temp gun like this to check the points on the system, should show where the issue is? Heat load, coolant flow or air flow issue?
This is how we troubleshoot industrial cooling systems.
409641
 
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