Model A Thermosyphon with NO Waterpump

[Tom Wesenberg]

Since the Model T did OK with no waterpump and only ran a fan with thermosyphon, I'm wondering if anyone has ever tried this with the Model A?

I know guys have broken off fan blades to make it home in an emergency, but I'm talking removing the impellor blades and using just thrermosyphon with the fan. It would be interesting to try it, but I'd want to have a temp gauge to monitor the engine.

Years ago I read that the fan wasn't really needed in cold weather, and I removed the fan from my 1949 Chevy 1 1/2 ton truck one winter day. The engine promptly started to run too hot so I immediately put the fan back on.

[glenn in camino]

On my very first aluminum fan the pulley broke and the fan belt came off. The fan blades were ok, so I removed the belt and drove home. Everything was ok as long as I was moving, but it started to heat up at stop lights. I made it home ok.

[Greg out west]

Hi Tom,,


I had to do what you said when I broke a fan belt one night..As long as I kept moving, I was OK...Couldn't sit at a stop light too long or I was in trouble...I read someplace that Henry made it like the T a "Thermosyphon system" in case of a emergemcy


Greg out west,

[Ray in La Mesa]

I have run my A with out a fan when the belt broke on a long trip. It works fine while traveling above 20-25 MPH on level ground but in stop & go traffic it tends to heat up as the air flow is not enough to keep cool. Hills also make heat it up too much.

[Jon]

In 1972-73 I ran a Chevy Nova 6 cyl. for a year and a half with no fan. Put a good temp gauge in it and as long as I didn't stop for very long had no problems. I know that's not what you're talking about here but I need to get my post count up.

[ABento]

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John Deer tractors ran on the thermo syphon for years,but there is a necessity for the fan.

[Marco Tahtaras]

There is one thing that many responses don't take into account. With no fan belt you still have a water pump when you are driving. The air flow through the radiator does a pretty fair job of spinning the the fan and thus the water pump. I suspect a modern type steel fan would be less effective than the propeller type fan in this case.

[Patrick L.]

Some tractors have had no water pumps and I've had a Kubota for 40 years and 4000+ hrs with no water pump.

[P.S.]

Originally Posted by Marco Tahtaras

There is one thing that many responses don't take into account. With no fan belt you still have a water pump when you are driving. The air flow through the radiator does a pretty fair job of spinning the the fan and thus the water pump. I suspect a modern type steel fan would be less effective than the propeller type fan in this case.

Wow. Hadn't considered that. Leave it to you to contribute what most of us would have not seen and is so obvious. Thanks!

So what would happen if there was no fan on the end of the shaft and the shaft were not turning?

Also, did you get my email about the original un restored 29?

[Keith True]

I ran my 30 pickup for a summer with the water pump unhooked.I was cranking along at about 60 when I had a big crash and the whole truck shook so bad it felt like it was coming apart.I had lost one blade of an aluminum two blade fan.With a steel fan you can just break the other blade off and be on your way if other things are not damaged.Try breaking half of a cast aluminum blade off.You need tools.I had one of those belts made of leather links,I work on old equipment so I have it in rolls.I shortened it up to run the generator and kept driving.It didn't overheat so I drove it the rest of the summer.The main thing was that I was aware of it and drove it accordingly.I avoided traffic,and tried to keep air blowing through the radiator all the time.

[sidhartha]

I think to find the answer to Toms question you would have to remove the pump from the system entirely. Take the water pump off the car and put a plate over the front of the head. That would eliminate any restriction, along with any external force moving the coolant. Thus making it rely solely on a themosyphone system.

[redmodelt]

The question was not about removing the fan but the fins off the impeller or removing the impeller completely and say replace it with a collar that would hold the shaft. That would allow free flow of water. With the larger radiator and a fan I don't see why not. As stated above there are a number of units that don't use a water pump and the A's pump is there to assist the thermo syphon flow and some of them would run under pretty good loads.

[Randy in Illinois]

Is that why many model Ts were converted to waterpumps? I noticed both add on ones from the time. some look like they could have been from the factory. How good was a model T without a pump? Didn't they have a fan on and idler pully or something?

[Ron Lachniet]

My 1937 John Deere AR has a fan but no water pump, however it does have a large inlet port on the radiator. I have heard that making a good thermal siphon system is more scientific than it looks. I tried to use that method when I built a scale model of a cross motor Case and it didn't work at all. I ended up putting in a water pump.

[dumb person]

Originally Posted by Randy in Illinois

Is that why many model Ts were converted to waterpumps? I noticed both add on ones from the time. some look like they could have been from the factory. How good was a model T without a pump? Didn't they have a fan on and idler pully or something?

They seem to go ok without a water pump but i have overheated one once, due to a variety of factors against it including a steep hill. They have a fan but i drove one without a fan for ages, only putting it on again on the hottest of days.

[Jim Brierley]

a couple of years ago i was driving my tudor from home to yuma az. the water pump failed drastically. i found that i could slow most of the leak by cutting the fan belt and tying the pump in place. with a few gallons of water and my eye on the temp. ga., i was able to continue my journey. temp. held around 200 all the way.

[CarlG]

Neither of these address the original issue, but since the door was subsequently opened:

My Dad took the fan off of his 56 Fairlane when it was only a couple months old. It was still that way 10 years later when he sold it. That was in southern Arizona & New Mexico.

Only time I remember it heating up was when I was driving it on a paper route; lots of slow, stop & go driving. When I noticed that it was heating up, I just took it out for a 30-40mph burst for a minute or so and then back to the route when it had cooled down.

On our long distance tour last summer, one of our guys in a 30 Coupe lost a blade off his fan, so he just took ALL the blades off (he had a 4-blade steel fan) and ran it the rest of the way without a fan (about 500-600 miles).

[jm29henry]

I was on by a road where I could not pull off wwhen I did I found that the generator froze up and the belt broke I needed to go about another 10 miles as long as I moving the motor metor show slightly at a light it would climb to above the middle it never over heated please note this car always runs cool and I credit that to a great radiator. Its a original round tube I had it cleaned and flowed checked before I put it in to my car .It was done by A&B radiator in Ann Arbor Mi for only $60.00 dollar

[Hicktick]

I don't want to hi-jack this but say you lost the water pump and could not run the belt , what to do about the generator ??

If you run without a belt , wont it ruin the genny ??

[H. L. Chauvin]

1. Similar to many above, had only the Model A fan belt brake.

2. Opened driver's side hood & got up to about 35 m.p.h.

3. Could immediately "see" fan turning in wind & knew water pump was working.

4. With one side of hood opened more air could pass through the radiator because of the wind pressure on front & absolutely no air exhaust constriction on the rear side in the engine compartment.

5. To see if it helps to open the hood, maybe try opening one garage door on a heated garage to see how little cold air blows in ................ next, on the opposite wall, open the other garage door to see how much cold air comes in with a wind pressure just on one side -- never tried that ?????? .... neither did I ... my garage only has one garage door.

6. Oh well, like others, made it home OK.