Getting hot when idling for a long time

[bdtutton]

Hello,
I have an early 1914 Touring that runs so well that I often drive it 25 miles a day round trip to work during the summer. I watch my moto meter and even on really hot days the car runs a little warmer, but still well within the operating range. The only problem I have is when I get into a fast food drive through lane the temperature starts climbing towards the top of my moto meter as I sit in line idling for long periods of time. I have tried idling a little faster to pull more air through the radiator, but it does not seem to make much difference. Everything on the car is stock and the radiator is clean and the fan is a standard 4 blade design. I know the obvious answer is to give up fast food and stay out of the line, but I would still like to find out why it is getting hot when idling for a long time.

[Moxie26]

Is your coolant level and the radiator up to snuff ??

[bdtutton]

When I top off the coolant, some runs out when it gets hot until it gets to a level about a fingers length down from the opening. It stays at that level and I seldom have to add any. I am not sure what level it is supposed to be, but it seems to be happy at that level.

[perry kete]

Do you retard your spark when you sit in line or leave it advanced? If you retard your spark try advancing it some.

[Scott_Conger]

Getting hot when idling for a long time

yep
it's what they usually do...so don't do it

[Moxie26]

Maybe they work too slow at that fast food restaurant ...maybe time to pick another ? ... I do agree on keeping your timing advanced ..... If you have a water pump on the engine it may be pushing out coolant through the overflow pipe giving you that low level in the radiator.

[bdtutton]

I keep the timing advanced and keep the car running at a moderate idle.

[Scott_Conger]

aaaannnnddddd........if still gets hot
don't do that

[speedytinc]

You can always shut the motor off & push it to advance as needed thru the drive thru.
Makes for a better show.

[Jerry VanOoteghem]

When I top off the coolant, some runs out when it gets hot until it gets to a level about a fingers length down from the opening. It stays at that level and I seldom have to add any. I am not sure what level it is supposed to be, but it seems to be happy at that level.

That sounds like a good, healthy level.

[JohnM]

You could always park it and walk aaaalllll the way inside. All kidding aside, I have a new Berg's radiator and the temp creeps up very slowly when sitting in traffic but it has never boiled over. Even in the best condition, T's are not as efficient as we are accustomed to.

[TWrenn]

Yep. Normal. Avoid long idles like Scott said.

[HalSched]

Old radiators loose their efficency. You will be surprised what difference a new radiator will make.

[jiminbartow]

Totally normal. Model T’s were not designed to sit idle. Many members here will concur that boiling over is a common occurrence with Model T’s while driving in parades. The cooling of the thermo-siphon system relies on the wind blowing through the radiator by the forward movement of the car assisted by the fan pulling the air through from the engine side. While the purpose of the fan is designed to continue the flow of cooling air through the radiator when the car is not moving forward, the idling speed of the engine does not allow the fan to spin fast enough to pull enough air through the radiator at a fast enough speed to cool the boiling water leaving the block and entering the radiator thus, the thermo-siphon basically comes to a standstill as the water stops cooling and ceases to continue to push the water through the radiator and up into the block in order to keep the water moving. I don’t normally recommend water pumps, but in your case, it might be a consideration. It’s too bad that there is not a water pump with a bypass that can be activated during idling and deactivaed when driving regularly, as the situation commands.

When I worked on my T while it would be running while standing still, I would keep it from overheating by positioning a big industrial fan in front of the radiator. Jim Patrick

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[JohnM]

Remember, the model T was designed first, then came the traffic jams.

[Erik Johnson]

Richening the fuel mixture will help it run a little cooler.

[perry kete]

So, What did the people do when they sat in line at McDonald's drive thru during the twenties?

[JohnM]

They passed the flask around.

[TXGOAT2]

The Model T fan doesn't move a lot of air. If it did, it would consume a lot of power. A clutch fan would be a solution, but you'd have to make your own. Another solution would be to mount a water resevoir somewhere on the car and plumb it to a windshield washer pump, or use a hand pump to air up the reservoir. Connect the reservoir thru a valve to a couple of small spray nozzles arranged to allow spritzing the radiator when the temperature goes up.

[Norman Kling]

I don't remember any drive throughs when I was a boy. There were drive in's where a car hop would take your order and then bring it on a tray and clamp it on your window, or on the steering wheel of the driver's seat. We actually parked the car and turned off the engine while dining. It seems like we used to go into McDonalds or walk up to a window to order.

We have a member in our local club who has an electric fan inside the radiator. It can be run while idling or even for a short time after parking. It is also great for parades.
Norm

[TXGOAT2]

As long as the system doesn't boil over, you're OK. If your license plate is in front of your radiator, you might try moving it. Be sure that the radiator core isn't loaded with paint, dust, bugs, grass seeds, lint, or anything else that could obstruct air flow. You may have a radiator with loose fin syndrome. It would also be a good idea to check the engine temperature with another gauge. It may not be as hot as you think, assuming it doesn't boil. Model T fan belts can slip a lot and not squeal. Be sure the fan belt is tightened per the book, and not excessively oily.

[TXGOAT2]

I don't know how many different fan and crankshaft pulleys were used on Model Ts, but if you can locate a smaller fan pulley that will fit, it will speed up the fan. A larger crankshaft pulley will do likewise.

[kmatt2]

I see that you have a 1914 T, so if you have a 1914 engine you already have the smallest fan pulley and the narrow nose pan won’t fit a bigger crank pulley. I once had a 1920 T engine that had been used to drive a flat belt to run a saw mill. That engine used a after market five blade fan with slightly higher pitch blades from the 1920’s or 1930’s. I had that five blade fan on a speedster that had a old Ford radiator that wouldn’t cool in traffic. Until I had the money for a new radiator that fan worked fine to keep the car cool in traffic. If you don’t want to use a water pump you could look for a after market fan that will fit with your brass radiator.

[Russ T Fender]

I live in Florida and I have a '14 touring. It gets real hot there and I often wind up sitting and waiting for draw bridges to come down. My car has a 25 year old brass works round tube radiator and it clearly gets hotter sitting like that but it never has boiled over. I sometimes have to resort to racing the engine at a fairly high idle speed, not just raising it a little, but that keeps the temperature down enough even on the hottest days. I watch the motometer and if I see it starting to go up I increase the idle speed right away to keep it from building up too much heat and that seem to work well.

[greenacres36]

I don’t know if it amounts to anything but I have put water wetter in my cars. Does it work? Maybe.

[KMcoldcars]

Water Wetter does work. I used it on my 1974 Pantera. They are notorious for overheating when idling, but I could let idle in my driveway in the summer sun for 30 minutes with no overheating.

[bdtutton]

I thought about adding a radiator fan shroud to help with cooling, but I am not sure how much it would help. I know that in 1917 Ford started putting radiator fan shrouds on the Model T's, but discontinued it after a while. I am not sure if it was discontinued because it did not help or if it was discontinued because it reduced the cost of the car...or both. Has anyone tried using a radiator fan shroud on a Model T ??? I know a nice electric auxiliary fan would do the trick, but with the exception of lighting improvements my car is restored to original.

[George House]

Try Water Wetter first Bryan then don’t go to the drive thru during lunch rush...

[RajoRacer]

Here's an all original 1917 shroud - quite rare !

[Professor Fate]

I use an infrared thermometer to look at the radiator.
It shows 130's at the bottom, and 170's to 180's at the top after shutting down from a ride. Cold water settles to the bottom of the radiator.

[TXGOAT2]

The late style cars had the fan mounted higher, which Ford claimed improved its efficiency. If a full size fan could be mounted higher in the early car, more of the fan draft would be concentrated on the hottest part of the radiator core. I doubt there is room to do this with the lower radiator, but if there is, it would be an easy and reversable modification. Short of that, using the longest belt that is practical on the 14 car might allow moving the fan up as far as is practical with the stock mounting arrangement, thus gaining some cooling efficiency.

[Luke]

Bryan,

Unsurprising to see all the responses, Model T's and cooling always seem to raise robust discussion!

FWIW I tend to favour pragmatism over absolute orginality and see no issue with a period water pump mated to a clean(ed) radiator.

However you've also hit upon an important accessory that should make quite a difference, and which Steve appears to have confirmed is a known (original) part - the fan shroud.

It has been known for a long time that a shroud will usually improve the axial flow of air resulting from the fan rotation, noting that it would assist airflow both through the radiator and over the motor. Without it there is quite a lot of 'wasted' radial air movement, and an undirected airflow will likely miss the extremities of the radiator. This is why most modern vehicles have a shroud (there are many papers on this - for example: Analytical Investigation of Fan Shroud on a Thermal Heat Exchanger for Automotive Applications, B Ashok, SAE Technical Papers 2017, and Experimental study on the effect of shroud on performance and flow field of automotive cooling fan, Xiaowen, Suping, Yanjia, Guang, Khalighi, & Johnson, Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering 2011).

It would be interesting to know exactly why the Ford shrouds were originally brought in, then stopped, and whether in practice they assisted the Model T engine cooling much, but I suggest that from both first principles and latter day research that a shoud should have a noticeable affect on cooling and would be worthwhile implementing in your case, even in a temporary 'experimental' capacity. If you were to do this it would be particularly useful to take some thermal images of the motor and radiator operating before and after shroud installation - there's nothing wrong in using modern techniques to contribute to the general body of knowledge - and possibly solve an ancient problem

[Scott_Conger]

If you want to be cooler at idle, put a shroud on it...if you want to be cooler at speed, take it off

[TXGOAT2]

No doubt a fan shroud would help, but making one would be a challenge and it would limit access to the timer. Fan belt adjustment range would probably be limited. I believe Ford put a fan shroud on a few early production Model A cars, but soon abandoned it.

[bdtutton]

Thank you everyone for all the great responses. I have worked hard to keep the car the way it was when it was built in October of 1913. From the responses it seems that adding a water pump would probably solve my problem and I am sure people were adding water pumps to cars during that time and I doubt the car will be thrown out of a car show for having a water pump. I will think about it over the winter....
.
I love this forum and all the good people on it...

[jiminbartow]

I read in Bruce McCalley’s Model T Encyclopedia that in 1909, water pumps were applied at the factory to the first 2,500 cars, so it is possible that having a water pump on your year T might be deemed authentic for a privately owned car of that vintage since it is possible that an early owner might have recalled this and determined it was a good idea for him, his circumstances and his car and that 1913 is recent enough to 1909 that Ford dealers may have still carried the water pumps in stock, so *you might want to try and find an early original style water pump. In the early years, the radiators were much smaller than in later years, so naturally, the early ones were not as efficient at cooling the water using the term-siphon system, which was not fully developed in 1913.

*Having found pictures of an original 1909 water pump, it may or may not be possible to utilize one on a post 1909 T, but it is interesting to look at.

Pat’s great suggestion to remove the license plate from the front of the radiator reminded me that, back in the day, there was an accessory that was guaranteed to to cause your T to boil over though it was meant to help. Look at how much radiator area it covers that prevents the flow of air. If you have one, remove it and display it on your garage wall instead of on your T. Jim Patrick

[TRDxB2]

Just curious - I am sort of keep a record... Do you have the engine splash pans (as the are referred to) installed.
Theses have a purpose to assist in airflow around the engine and thorough the louvers of the hood by creating a negative pressure zone.
Water pumps...
If you consider where the impellers of Model T water pump are, you might realize that they cannot move coolant where the fluid level is lower than the impeller. They are nothing like a modern water pump in a pressurized system. All they can do is push coolant that is delivered to them via thermosiphoning action.

[Erik Johnson]

Canvas desert water bags are for keeping drinking water cool in hot climates, not for keeping the radiator cool.

The water soaks through the canvas and, as it evaporates, it cools the water inside the bag.

I believe hanging it on the front bumper, headlight bar. door handle or sideview mirror was common to allow for the most air to rush over it. I don't think hanging it on the radiator neck and directly against the radiator fins of an early automobile is a good idea. If you had a later car like a Ford V8, hanging the bag on the front grill probably wouldn't be as much of an issue because there is still air space between the grill and the radiator so air would still circulate around the radiator even though the grill was partially blocked.