Thermonsyphon

grandpa Love · Jul 4, 2022

As I cut grass or cultivate my garden on 100 degree days with my Cub or A I wonder...... Why don't more tractors use the thermosyphon cooling system? Works great on these (and others) . Why wouldn't a Ford N series work the same way? Why did some manufacturers use water pumps and others didn't?

Steve@Advance · Jul 4, 2022

Circulating the coolant with a pump gives a better overall temperature distribution.

If you could measure the temperature in various places, I suspect there would be big differences between the cylinders, something that is very undesirable for performance and engine durability.

The advantage was one less thing to go wrong where parts are unavailable.

Crazy Horse · Jul 4, 2022

I had a Farmall A once that was difficult to get up to a hot operating temperature ...... even with the rad shutters closed. A thermostat might have cured that issue, I don't think it had a thermostat did it?

whereswaldo · Jul 4, 2022

It would take a HUGE radiator to do this. Along with large pipes to circulate coolant. As it is, my Ford 8N will boil it's antifrreeze when bushogging my pasture. Now, it does take about an hour to achieve this, but once it starts, it's constant. I have a thermostat and the water pump does it's job but there's no way a thermo-syphon system would work without greatly increasing the cooling system to an unworkable size.

grandpa Love · Jul 4, 2022

Farmall cub has a small radiator..... And doesn't hold much coolant.

coonie minnie · Jul 4, 2022

Thermosyphon was great when it worked. But as mentioned you needed a big radiator and cooling system, clean equipment, an operator who knew how to adjust the shutters, etc. As engines grew more efficient (or at least powerful for their size) it didn't work as well. Higher RPMs, higher compression, more fuel burned per cubic inch all meant more heat to disapate.

Here's an example- John Deere G 415 cubic inch, 50 hp on gas. Thermosyphon, 10 gallon radiator and cooling system, known to get hot. JD 4020, 95 hp, 404 cubic inch, cooling system holds maybe 6 gallons? Less than the G.

John Deere ended up putting water pumps on a's, b's, g's at the end too because copper for radiators wasn't available due to Korean war demands. Steel didn't radiate the heat as well as copper did, and the waterpump was necessary.

It was a cool system, but the tractor world outgrew it.

NY 986 · Jul 4, 2022

As said better distribution of coolant through system. I was told that this mattered immensely on very hot days with the tractor under full load.

Gene Davis (Ga.) · Jul 4, 2022

Thermosyphon cooling was good in the days of low horsepower out put from engines, but it went away for the same reason that John Deere finally abandoned their famous 2 cylinder engines, it just was not up to the demands of the timees anymore.

coonie minnie · Jul 4, 2022

...and a displacement of 60 cubic inches. the relatively high location of the radiator to the engine coolant discharge helps, too.

coonie minnie · Jul 4, 2022

I'd add according to tractorhouse coolant capacity on a cub is almost 2.5 gallon, quite a bit for a 60 cubic in engine I'd think.

Geo-TH,In · Jul 4, 2022

My 1950 Farmall c doesn't have a water pump.
I thought my temp guage was broken.
Installed a new one.
Guage wasn't broken.
Tractor doesn't get hot enough for it to register.
Go figure.

Gary Mitchell · Jul 4, 2022

Steve, that might explain why, with a lot of 113's I've opened up, the further back on the head you look, the worse condition the valves, seats are. # 4 exhaust was generally the first to go, as I recall. Perfectly logical. gm

GreenEnvy · Jul 4, 2022

I agree. The first JD tractor to use thermosyphon was the D and back then less was more meaning if you could get rid the of the water pump, less things to go wrong. The 2 cylinders lent themselves to the thermospyhon system being with the larger internal passages, only 2 large cylinders to cool. Even the R was thermosyphon.

onefarmer · Jul 4, 2022

I had just delivered the anhydrous applicator back to the dealer and on my way back home when the fan belt shredded. This was before cell phones so I kept going until it boiled over. I made it 10 miles all the way home. It never over heated. MF175. It must have been thermo-syphoning.

john in la · Jul 4, 2022

For the same reason your Farmall uses a thermosyphon system rather than air cooled.
The bigger and more efficient the motor gets the more cooling it needs to keep it cool.
And yes I owned an air cooled 2 cylinder tractor built in the late 70's.

Leroy · Jul 5, 2022

You take your tractor and hook it to a plow and go out and work it all day and you will see why they started putting water pumps on the supper series.

Leroy · Jul 5, 2022

Ford learned the hard way why the thermosiphan would not work with the early Fordsons. They would boil over in getting in hard work. That is why the aftermarket started building a kit to put a water pump on them. Very few got that kit tho as by that time most were retired from hard work or the owner never heard of the kit. And I have seen them with an add on tank of about 5 gallons mounted on top of the radiator. This gave more water capacity to try to cool the engine.

Thermonsyphon

grandpa Love

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Steve@Advance

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Crazy Horse

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whereswaldo

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grandpa Love

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coonie minnie

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NY 986

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Gene Davis (Ga.)

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coonie minnie

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coonie minnie

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Geo-TH,In

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Gary Mitchell

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GreenEnvy

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onefarmer

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john in la

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Leroy

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Leroy

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