Thermo-Syphon

[JAKEFORD]

My old Prefect had a Thermo-Syphon cooling system that worked OK most of the time. Eventually I put a water pump on it and it seemed to cool better after I did that.

Since the Prefect was a scaled down Model A, I wonder if the Model A had a similar setup with no water pump. I think the Model T used a Thermo Syphon system but am not sure.

Any comments?

[MrTube]

As far as I know, all "A"s had / have a water pump.

[BILL WILLIAMSON]

Chief said that the "T" system worked pretty fair, if you didn't drive TOO FAST.
Bill W.

[jeep44]

Farmall Cub tractors never had a water pump-just a fan

[JAKEFORD]

I remember the old Prefect without the pump worked better in cold weather. In hot weather it would often boil.

I guess it worked OK in England, where it was intended to be, because the temps were more moderate.

[CarlG]

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What model year was your Prefect?

[JAKEFORD]

It was a 1951 4 door.

I bought the water pump through our local ford dealer who used to handle them when new.

[Willie Krash]

My guess and no more than that is a thermo-siphon efficiency is tied to the radiators cooling efficiency. As it ages and plugs it cant not provide the needed temperature differential to siphon effectively. Perhaps this is why so many T's use a pump.
I think perhaps I'm stating the obvious.

[Ron in Quincy]

The Model A engine is also Thermal Syphon.

If you break a fan belt you can drive your A, it will only heat up when you slow down and no air is passing through the radiator. At normal driving speed it will run about the same as if you had the water pump engaged. If your battery is fully charged you can get about 4 hours of driving.

We had a club member who had a fan hub break, we removed the fan belt and he drove home 60 miles and said his A ran just as cool as normal except when he slowed down.

Ron

[CarlG]

Originally Posted by Ron in Quincy

The Model A engine is also Thermal Syphon.

If you break a fan belt you can drive your A, it will only heat up when you slow down and no air is passing through the radiator. At normal driving speed it will run about the same as if you had the water pump engaged. If your battery is fully charged you can get about 4 hours of driving.

We had a club member who had a fan hub break, we removed the fan belt and he drove home 60 miles and said his A ran just as cool as normal except when he slowed down.

Ron

Since the fan is attached to the water pump, wouldn't the fan just "windmill" while the car was moving and thus cause the pump to turn as well??

[JAKEFORD]

On the Ford Prefect/Anglia the water pump in not behind the fan. The engine was designed for Thermo-Syphon and no water pump provision was made.

The after market pump mounted below and to the side and was driven off the fan belt. It was a small pump but worked very well and mounted on some spare holes in the area.

I remember this system was prone to air locks when you changed anti-freeze to the point where the pump wouldn't grab the fluid. You had to squeeze the hoses several times to get rid of the air lock. Sometimes filling the rad very slowly would do it too.

[CarlG]

Originally Posted by JAKEFORD

It was a 1951 4 door...

...

[Hoogah]

Originally Posted by JAKEFORD

Since the Prefect was a scaled down Model A....
Any comments?

I've seen this written here once before. In what way was the Prefect a scaled down Model A?

We had a Prefect when I was a kid. It was my parents' first car in the 1950s. I didn't know that they were also exported (I'm presuming) to the US, or were they manufactured there too.

[J Witt]

I ran an aftermarket pump on my 1912 Model T Touring. Even with the tiny radiator she ran fine in Tucson in 100 degree plus. It mounted on the side of the block where the water neck bolted on. It had flat belt and little bitty fan. I agree it probably helped when stopped, but it would overheat like a teapot without the pump at around 100 (degrees, not miles per hour)

[JAKEFORD]

The Prefect/Anglia were exported to the US/Canada in the late 40's and early 50's. I bought mine with my newspaper money savings for $75. It had only 42,000 miles but quickly earned the name "Defect".

It was a scaled down Model A in that the engine was similar but much smaller. In fact the distributor from the Prefect, they tell me fits the model A. The 3 speed transmission is scaled down and the rear end and driveshaft were scaled down with the torque tube. It had the buggy springs and similar shocks to the V8. The rear end ratio was 6.6 and gave a comfortable top speed of about 48 mph. Gas mileage was great, about 45 mpg.

I had cooling issues, head gasket problems, broken clutch release lever, mechanical brake problems and starter problems. I used the hand crank a lot. I kept this car 3 years in high school. It was a fun car and I learned a lot from working on it. It burned a lot of oil but was very reliable. I don't ever remember being stranded.

[James Rogers]

Originally Posted by BILL WILLIAMSON

Chief said that the "T" system worked pretty fair, if you didn't drive TOO FAST.
Bill W.

I have driven my T in July to the Grand Canyon at WOT and never had a heating problem. I never run a water pump on either and never have a problem running or at idle. I recommend to never use a water pump on a T.

[Gold Digger]

All John Deere tractors were the thermo-siphon system till some time in the late 50's or early 60's. I've pulled them hard all day in 100* weather and never had over heating problems.

[MrTube]

Can a thermostat be used with a thermo siphon system?

[JAKEFORD]

I never used one. I would think it would restrict the flow.

I used cardboard on the bottom of the rad in real cold weather to keep the temp up.

[MrTube]

I always insist on a thermostat, at least when possible. I guess there are some machines you just can't on such as a stock T.

Running an engine below 180-190F promotes wear and oil contamination. 160F is too cool and anything below that is just abusive.