Somebody posted a video on Model T Club of Facebook showing a steaming radiator. Some guys are claiming that it is caused by overfilling. I say baloney. Overheating can be caused by several things, but overfilling isn't one of them. Am I wrong?
An overfilled radiator will simply push the excess water out. It took me a long time to accept that the T will find a happy level and not push water out the top and bottom.
If the video shows steam then that is another issue entirely. As we all know, there are many causes of overheating ... Over filling is not one of them.
In my humble opinion you are correct. Over filling an automotive radiator will not cause over heating....period.
I overfill my radiator every driving season, and it spits out what it deems is not needed and is happy with that for the entire season. I have checked it several times, and its always at the same level. If you have a good radiator and a block and head that isn't clogged with debris, i would assume you could expect the same results. So, in my humble opinion, baloney indeed.
The only time I've seen water squirt out of my radiator was when I had a bad cap on it.
I overfill ever time
I at first said this pure bull but I checked with a buddy who has a Doctorate in thermo dynamics. He stated if conditions would have to just right it plausible however very unlikely.
I personally think he running hot and the only item on his T's cooling system that working correctly is the overflow tube
Methinks someone is confusing "overflowing" with "overheating".
My radiator has decided to leak again, so I am topping it off before I take runs, and a jug of
extra for along the way. As others have stated above, the truck will puke out what it seems to
consider excess and then fall into normal operating actions until I notice the motometer rising
a bit, so I then top it off again and repeat the process.
A new radiator is part of the currently in-progress engine rebuild plan, so this should all become
a non-issue when that gets installed.
I'm curious regarding what distinguishes a bad cap from a good one.all my model T's have caps that screw into the filler neck of the radiator. Heck I don't even bother putting a gasket in mine. The thermal syphoning is so efficient on mine that once it's found its proper level it doesn't squirt water from anything. And, by gosh, I don't have a water pump on any of them.
Another factor - Altitude
The enthusiast on the Farcebooks who suggests this, believes the radiator will "syphon itself", and offers no knowledge of the specifics, just that a lot of old timers say the same. I say that no syphon can take place, since the top of the overflow tube is above the level of the fluid.
I make it a point to read all threads dealing with overheating as I have been battling this with my TT. I often read the term "happy level" but no one ever puts a quantitative value on this term. Is it 1, 2, 3 quarts, a gallon? I understand that each T will be different but could we get a average value?
The last time I drove my TT before knee surgery I put about 10 miles on it. Starting with a full radiator and did not see the temperature gauge in the top hose get above 200 degrees I was a full gallon low when I got home. one gallon seems like a lot as it is only a 3 gallon system.
Steve - Interesting post you've started here.
You know, when you think about it, the fact that so many seem to think that overfilling a radiator causes overheating is almost inevitable! Just by the very principle by which the thermo syphen (sp?) works. This is a classic case where the Model "T" is unique. Thermal syphen works well and dependably, but it absolutely will only work at, or, VERY NEAR the boiling point. Because a bit of boiling, especially for minute or so after shutting the engine off is really pretty normal for a "T", and because many folks (especially "newbies) tend to fill their radiators to a level (overfilled) that they are familiar with in their "modern" car, this common bit of "rumbling" from boiling right after shutting the engine off (which of course is much more "audible" when the engine is shut off and not making all that noise) and because of overfilling, puking out a bit of water is normal, but mistakenly considered "abnormal" by the newbie!
In other words, just one more classic case of one of the many ways the Model "T" differs from the modern vehicles that we are all used to. Again, just "IMHO"......FWIW,......harold
As an "aside", not trying to be "spelling police" or whatever, but I do find word origins to be interesting. I think I spelled syphon incorrectly above, but I do know that many people call it "thermal" syphon when actually, the correct spelling is "thermo" syphon, and I'm not sure that perhaps that is a unique spelling of a word, or "term" that came about because of the Model "T"!
Now then, is "thermo syphon" one word, or two? Heck,....I don't know! (???) And who cares anyway, right?
The water gurgle after shutting down just shows that the thermo syphon is indeed working. The heat is being given removed as long as air is passing through the radiator. Once the movement stops, sufficient heat is absorbed by the small amount of water in contact with the metal to raise it to the boiling point, one the gurgling starts.
As far as the radiator cap , the only purpose of it and the gasket is to allow filling and keep water/antifreeze stains off the radiator.
By the way, thermo syphon is not unique to Ford, at least Chalmers also used it and I suspect other auto makers did as well since it worked and did not require a water pump that cost money and had its share of problems.
Harold, further to your comment.
I get 23,000 hits in Google for "thermal siphon" (it will accept "syphon," by the way, but prefers "siphon"). I get 287,000 hits for "thermosiphon" as one word and 40,900 hits for "thermo siphon" as two words. I knew the term before I bought my T because the 1936 English Austin I bought in 1974 uses the same system, and it was one word.
Hmmm,......"thermosiphon",......"thermosyphon",......??? I'm starting to wish I had not even brought it up! Ha,ha,....thanks Dick,......harold
Sorry Steve,......didn't mean to "derail" your thread,.....but then, it's interesting how sometimes a lot of just plain good "discussion" "just happens",......harold (:^)
Of all the interesting things associated with the model t, I find thermosyphon, or however you spell it , the most interesting. It's almost like magic.
Hal,....and isn't it interesting how it seems to be difficult for some of us to accept something so simple and foolproof, without trying to "improve" with some "modern" mechanical device like a water pump, thermostat, etc, etc,......harold
It must be magic. How does the water know which way to go?
It is kind of like a thermos.
You put something hot in there, and it stays hot.
You put something cold in there, and it stays cold.
How do it know?????
POST HOC ERGO PROPTER HOC (After that, therefore because of that.) The rooster crows and the sun rises. Therefore, the sunrise is caused by the rooster crowing. The radiator is overfilled and it boils. Therefore, the boiling is caused by the overfilling. I think that may be the kind of "logic" going on here.
David, your elevation is only about 1700'. There should be no boiling at 200º. If your thermometer is accurate, I suspect your loss of a gallon is due to leaking, not boiling out.
Thermosyphon does not require boiling to function. Warm liquid rises and displaces cooler liquid regardless of being at, near, below, or nowhere near the boiling point.
Thermosyphon works properly at any temperature, given a reasonably rust free block and a decent radiator.
My 1924 cut-off touring car (now a pickup) came to me with the stock thermo-siphon system and a new, flat tube radiator installed. I drove it 30 miles today in 93 degree heat and it didn't even gurgle after I shut it off, so I'm a happy camper.
I think what makes it harder to understand for folks starts with the old "Heat rises" idea. While heat does indeed rise, people seem to just accept that and never really understand why. It's magic, right? Well, the only reason 'heat rises' is because it is being displaced by something cooler. It doesn't just magically rise. It all comes down to a difference in density and gravity. When most things heat up, they become less dense and when they cool they become more dense. When you mix two things of different densities, the one which is more dense will go to the bottom due to gravity. As it does so, it pushes anything less dense upward and takes it's place. That's what happens in the radiator. As the water is cooled, it falls to the bottom of the radiator which pushes the warmer water in the engine upward and into the top of the radiator.
The beauty of it that the bigger the difference in temperature, the bigger the difference in density. The bigger the difference in density, the faster it flows. That is why you hear people say the thermosyphon system is 'self regulating'.
I love. The sound and smell of a hot T.
If you over fill the radiator the T pushes the extra out.
If you go too slow (parade) it makes steam and funny noises.
If you combine too much water and slow speed you get a dramatic show.
When you stop the T likes to gurgle gurgle. It is what a T does.
A T is not a modern car.
It is a Model T and does what it wants to do.
Royce is entirely correct about boiling is not necessary to induce a thermosyphon flow.......only a temperature differential.
Just because an engine is boiling does not necessarily mean it's over heated either.
I owned a 10-20 Titan as in the photo.
The part of the photo I did not black and white out is the water return pipe from the engine.
You will notice it is not only high above the engine but also high above the tank so there is no completed circuit.
It's only when the engine is up to temperature that STEAM goes up and through the pipe back to the tank.
Some of the steam condenses before and inside the huge cooling tank and they will evaporate many gallons of water in a days work.
As long as there is water above the hot parts no damage will occur.
In a Model T is there is no extra room for, pretty much, anything so if it's 3 quarts low you're probably in trouble.
There are no leaks in the cooling system all the water I am missing after the drive is blown out the over flow pipe. What I would like to know is what is the "happy level" how low is everyone's T, mine is a gallon low so I know that is to much for a 3 gallon system.
If water spews out around the cap, your gasket is missing of bad. It is normal for the water which expands with heat to go out the overflow pipe which directs it under the car. Normally you would not notice it unless it is steaming.
The below assumes correct coolant level in radiator There are several causes of actual overheating.
1. dirty block and clogged radiator which impedes the flow of coolant.
2. Worn engine with burnt valves and rings which makes the engine work much harder to pull the car, especially uphill.
3. Old radiator which is clean and does not leak, but has poor heat conductivity between the tubes and fins. This can also be caused by painting the radiator with too thick or wrong type of paint.
4. Very hot weather and pulling a very steep hill.
5. Too lean mixture.
6. Retarded timing. Note both lean mixture and retarded timing will also cause valve damage and a red hot exhaust manifold.
7. Very tight engine which has not been correctly broken in.
8. Oil level too low. Yes, the oil also will help reduce the heat of the engine both by conducting it away from the engine and by reducing friction
Anyway I have put these things in the order which I think is most likely. The spark advance and fuel leanness issues are less likely caused, but are easiest to correct. The worn engine can be checked by a compression check and the oil level by crawling under and opening the petcocks.
Modern cars have a pressurized cooling system which raises the temperature for boiling. However the T was not made for pressurization and you might have problems blowing freeze plugs or gaskets if you try to pressurize a T.
I have 3 Model T's and live in an area with quite hot summers and steep grades, but very seldom overheat. When kept in good repair they don't have a heating problem.
I can't say how low mine is, but I can say that they both get down to a point and then stay there. If it keeps spitting it out until it is so low it actually overheats, then your radiator ain't a doing its job. Get it up to temperature and then see if you can hold your hand on the pipe running from the bottom of the radiator back to the engine. If you can't, the radiator is not cooling properly.
'E v8s gave water pumps and non pressure systems and will push water right out the overflow pipe and if you really want to get a row started, get into a discussion about how to cool a flathead v8! The only real answer is an new radiator core!
I love my water pump.... Jerry.
I love my Berg's radiator.
I bought a junk engine with a water pump on it. Someday I'd like to sandblast and paint the water pump. No better reason than it would look nicer hanging on the wall. But for right now I'm busy trying to get the engine apart.
I got lucky that all my radiator needed was a good boiling out from a radiator shop. Works great. My motometer barely gets into the circle unless it's a very hot day to begin with.
I bought a new Bergs radiator for my 24 Coupe, filled it almost to the top with a 50/50 mix of water and anti-freeze.
I don't even think about whether its to much water or not enough.
All I know is no more boiling over or worrying about getting hot.
That's all I know. Honest.
Cooling an engine is magic. I run my T with 100% permanent antifreeze - green stuff - with no problem. Have a Nova hit-n-miss that has a water jacket on the top of the cylinder head, it is cooled with old motor oil. Yes the thermo cycling process is magic.
My old 1930 McCormick Deering Farmall Regulator used Thermo-syphoning as did my 1935 McCormick Deering Farmall F12. Neither tractor ever overheated regardless of how hot it was outside and what I was using them for. They both had some patched up soldered shut radiator tubes. They both found their optimum coolant level. Thermo-syphoning definitely wasn't exclusive to Ford and was an accepted and efficient cooling method for a few different engine manufacturers.
My Dads 1938 McCormick Deering Farmall F14 also used thermo-syphoning and leaked like a sieve. Dad would dump pepper, or horse biscuits or ground oats into it and used it for many years skidding saw logs and running his buzz-saw. He'd dump hot water in it and crank it up in the morning and then top it off throughout the day. At night or when shut down for an extended period he'd drain the radiator. Then he found Bahrs stop leak. It was a wonderful thing. When he could afford it he'd put the stop leak in instead of the pepper or equine fecal matter. He even went so far as to put some Prestone in the radiator but still didn't trust it and he'd drain the radiator each night.
Dad had a couple old Ford logging trucks with flathead V8's. The water pumps and the radiators leaked on both of them. It seemed I was never going to get away from leaking cooling systems but we seldom had a problem with overheating.
An overheating Model T engine can have a number of causes - but it's NOT due to "over filling", the radiator will expel excess water through the overflow in the neck of the radiator filler.
My Model T overheated recently - the cause: lack of airflow...
If you listen carefully at the start of the video, you can hear the last bit of "gurgling" - proof that the thermosiphon was working - overtime!
But of course there can be other causes.
I wonder if the problem here is filling the radiator full - up to the cap. If you did that you wold have about an extra gallon of water in the radiator. While driving, as the water heats up and expands, any water above the overflow tube will overflow. As long as you have water over the tops of the tubes and part way up the baffle plate you should be OK; given the radiator is up to the job.
My "Happy Level" for my round tube brass radiator is about 2 inches above the core tubes. That is, if I stick a stick down there till it hits something, its 2 inches wet.
Yesterday I found the remnants of a stick in my block when installing a Z head. The cooling system had been doing a good job anyway, and must be better now.
I've never heard of a home remedy that includes added the end of a stick to a radiator, but you might have just explained how it got there.
Somebody should make a gas and water level "dipstick" for us. Has anyone here seen one? We just need the measurements to make our own.
Mopar Slant Six and V8 engine blocks sometimes have pieces of wire in the water jackets. The wire was used to help hold the sand casting cores in place when the block was poured at the foundry.
Both pieces of wood were rotten and about the size and shape of a AAA battery. My shop vac pulled them out with some encouragement from a screwdriver.