overheating

[Maclab58]

I know this topic has been worn out here lately,but here we go again............. My only question is since I am not running a thermostat in my car and it is routinely 105 degrees in the afternoon is the coolant circulating through my radiator too fast to get any benefit from the fan? will a thermostat slow the rate of travel through the radiator to cool any more efficiently?

[Mitch//pa]

imo even though the stat is open at 160 it will still slow the flow some to keep the water/coolant in the radiator longer for the benefit of cooling it more. i have already on modern cars punched out the stat and left the body for just that purpose.

[skip]

If your not loosing coolant and not making steam and not leaking coolant out past the radiator ornament cap and doing it on 2-1/2 gallons, than your not overheating regardless of 'time in the tubes or air through the fins'.

Don't over engineer a simple system.

skip.

PC/SR I think he means the outdoor temperature in the Texas afternoon is 105 deg F. The running car I'm guessing is maybe 165 to 185 water temp. Still far below 212 deg F [with straight unpresserized water]. He's not making sludge till winter time.

[PC/SR]

Since you are apparently not overheating as Skip says, the next question is if you are running hot enough. You should be 160 or above. Too low a temp makes sludge.

[FL&WVMIKE]

Mitch//pa ......................
I have wondered about this for a while. If you keep the water in the radiator longer, to cool it better, are you not keeping the water in the block longer, to heat it ?
It works both ways. If you speed it through the block to keep it from heating, you are also speeding it through the radiator to keep it from cooling.
My question - does it really make much difference ?
Now to answer my own question, it must help to speed the water through, as SKIP HANEY of Florida, rebuilds V8 water pumps, that pump more water and he cures many flathead V8rs heating problems.
MIKE

[Tom Wesenberg]

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Originally Posted by FL&WVMIKE

Mitch//pa ......................
I have wondered about this for a while. If you keep the water in the radiator longer, to cool it better, are you not keeping the water in the block longer, to heat it ?
It works both ways. If you speed it through the block to keep it from heating, you are also speeding it through the radiator to keep it from cooling.
My question - does it really make much difference ?
Now to answer my own question, it must help to speed the water through, as SKIP HANEY of Florida, rebuilds V8 water pumps, that pump more water and he cures many flathead V8rs heating problems.
MIKE

I agree with your thinking on the time in the radiator and time in the block.

I'm not familure with the flathead V8 heating problem specifics, but I wonder if there were some "dead zones" where the water didn't move well and tended to overheat in that spot? Then a pump which move more water might get that "dead zone" moving some.

I installed a thermostat mainly to keep from adding 2 to 3 quarts of coolant every 50 miles. Since adding the thermostat, I haven't had coolant loss.

[PC/SR]

There have been many posts and articles about this. The thermostat "holds" water in the block until the T stat temp is reached. Thermo siphon and pump pressure then move the hot water to the radiator top and in a non-pressuriuzed sysem such as the model A, gravity and heat transfer to air then take over. As a general propostition, slow water movement will remove more heat than fast movement. Others will know more than me and can explain the dynamics of it.

[glenn in camino]

I think your problem is a clogged radiator. I run a 160 degree thermostat with a recently rodded out radiator. My temp guage registers 160-170 in any kind of weather. Have your radiator rodded out and I think the problem will be solved.

[Maclab58]

had the radiator rodded out before i ever fired it up. been an ongoing problem.

[Bob S]

Mike,
I too have thought about that, and I think that the laws of thermodynamics support what you say. Another way to look at it is: If you push the water through the radiator twice as fast, each gallon that goes through looses half as much heat, but there are twice as many gallons going through in that same amount of time, each one of them loosing half the heat. So the end result is the same. Same thing in reverse in the engine.

I do think, though that there may be a difference in HOW it cools the block due to the fact that the Model A doesn't have a bypass to circulate water when a thermostat is closed or partially closed. With a closed thermostat, the water leaving the engine is kept at the desired temperature, but the water in the radiator cools a lot (because it is traveling slowly), and therefore enters the block at a low temperature. The water in the head may be hot, but the water in the cylinder jacket can be much cooler. With the thermostat open (or no thermostat) the water flow is faster, doesn't cool so much in the radiator, and enters the bottom of the engine at a higher temperature. I've done some testing, and found that with a marginal radiator and no thermostat, there was only a 10 degree difference between the water entering and leaving the radiator, which also means that the water entering the engine was only 10 degrees cooler than that leaving. With a better cooling radiator (and a thermostat to maintain the same engine temperature), the temperature difference was more like 40 degrees. So, the bottom of the cylinder water jacket was running about 150 degrees while the head was 190. Modern engines avoid that by having a bypass to recirculate the hot water when the thermostat is closed. Does that temperature difference matter? I don't know. Model Ts always have that kind of temperature difference because of the 100% thermosiphon, and they don't seem to mind. It does seem clear though that faster water flow results in more even temperature throughout the engine as Tom suggested, but in cold weather, going without a thermostat would give more even temps, but way to cold. Using a thermostat would give higher temperature in the top of the engine, but lower temperature in the bottom where that very well cooled radiator water enters. It seems that a super-cooling 10 fin, flat tube radiator that could keep it cool in the summer desert heat would not be the best in cool weather where a radiator that looses less heat would result in less frigid water entering the engine. I guess the obvious solution would be to cover the radiator in cold weather. Or add a bypass with a valve that could be opened in cool weather. Or just do nothing and enjoy the car. It's gotten by just fine for 80 years. This may all just be an academic exercise, but it's fun to think about this stuff.

[Paul from Maine]

I had chronic overheating problems until I removed the head and cleaned out the water jackets. Using a magnet, I removed enough rust to fill an 8 oz. coffee cup. Then my old round tube radiator could maintain about 190 degrees. I felt that was marginal and sprung for a new radiator. I ordered it from Tam's and had in the car 26 hours later. Without the thermostat, the highest temp I could manage with the new radiator was 135. With the thermostat, she maintains a steady 160 easily. My advice- clean out the water jackets and buy a new radiator.

[Jim/GA]

Originally Posted by skip

If your not loosing coolant and not making steam and not leaking coolant out past the radiator ornament cap and doing it on 2-1/2 gallons, than your not overheating regardless of 'time in the tubes or air through the fins'.

Don't over engineer a simple system.

skip.

PC/SR I think he means the outdoor temperature in the Texas afternoon is 105 deg F. The running car I'm guessing is maybe 165 to 185 water temp. Still far below 212 deg F [with straight unpresserized water]. He's not making sludge till winter time.

OK, so if you ARE leaking coolant out past the radiator ornament cap, and the temperature gauge in the gooseneck says you are 170 degrees degrees (well below water boiling point), and there is a baffle in the radiator upper tank...

what's the problem?

Blown head gasket?

I would be happy to run an engine at 170 degrees all day ... not really that hot ... but having all the coolant blow out on the windshield any time you try to run 45 MPH is tiresome.

Looking for ideas.

[Ron in Quincy]

Correct me if I'm wrong, coolant doesn't make an engine run cooler, coolant raises the boiling point of the radiator fluid content and also protects against freezing ?

Ron

[1931 flamingo]

Ck your timing. Ck your timing. Ck your timing. I think in this post coolant=water. If not diff in temp is neglegible, he's running hot and wants it cooler.
Paul in CT

[Jim/GA]

Yes, coolant here is just water with a bottle of rust inhibitor added. No need for antifreeze in South Florida. I did not think 170 was all that bad, temperature wise.

Flamingo, you think timing is not advanced enough? Funny you should mention that. I don't think the breaker plate rotates all the way around until the arm hits the notch in the distributor cap. It seems to hang up on something.

This is my dad's car, makes it hard to diagnose from long distance.

[1931 flamingo]

Jim/TX: From what I've been able to pick up from this forum on overheating is that radiattors are plugged or system is dirty AND timing is not set correctly. If no flow thru radiator you get coolant that doesn't get cooled and if timing not correct same thing. JMO
Paul in CT

[CWPASADENA]

Originally Posted by Bob S

In cold weather, going without a thermostat would give more even temps, but way to cold. Using a thermostat would give higher temperature in the top of the engine, but lower temperature in the bottom where that very well cooled radiator water enters. It seems that a super-cooling 10 fin, flat tube radiator that could keep it cool in the summer desert heat would not be the best in cool weather where a radiator that looses less heat would result in less frigid water entering the engine. I guess the obvious solution would be to cover the radiator in cold weather. Or add a bypass with a valve that could be opened in cool weather. Or just do nothing and enjoy the car. It's gotten by just fine for 80 years. This may all just be an academic exercise, but it's fun to think about this stuff.

This is why they made "WinterFronts" for Cold Weather. They would partically block the air flow thru the radiator allowing the coolant to be maintained at a temperature closer to the operating temperature of the engine. For those with a Hot Water Heater, it also made the heaters work a lot better. If you look at Big Trucks, they will have shutters or some device to partly cover the radiator for cold weather operation.

In the "Old Days" when I was going to school in Missouri, during the winter, we would use a piece of cardboard as a "Poor Mans" WinterFront to block off part of the air flow thru the radiator.

Chris

[Ron in Quincy]

I had a winter front on my 34 Ford 2D when I was in High School. It was made for the 34 and had a zipper in the center so you could control the opening. Couldn't afford Anti-Freeze so would drain the radiator every night when it was expected to freeze.

Good lord thats been over 65 years ago, where has the time gone ?

Ron

[1931 flamingo]

CWPASADENA: most of us who live in the colder (winter) sections of the country are familiar with two types of t/stats. One for winter and one for summer, or for an engine with a super efficient cooling system, believe w/fronts were for extreme cold conditions where cooling systems were efficient. Remember stories of lighting fires under oil pans so engines would turn over because oil was so thick? Another thing is ethyline glycol type anti freezes didn't come into play until later on, I can remember using alcohol based coolant in the late 50's, cost at that time was also a factor. Sorry for my rambling.
Paul in CT