Fan shrouds

P

Peyton

Senior Member
This is to get opinions on cooling benefits of fan shrouds as pertains to the Model A (1929 to 31).

It's going to get hot here in Jacksonville pretty soon and I fear what this might bring to my Model A which tends to run about 190 on a 80 degree day. Long idle duration might bring the temperature up to 200.

I still have a long way to go before I can call myself an expert on the Model A. Last nite while doing research for a "modern car" radiator change, I first heard the terms "push" and "pull" fans. I believe that the Model A car has a "pull" type fan --- pulls air thru the radiator toward the engine. I swear --- I didn't know that until last nite. I also learned that a Ford 9n tractor has a "push" type fan --- pushes the air thru the radiator away from the engine. Please correct me if I'm wrong here.

My research indicates that the Model A only benefits from a fan shroud at speeds under 20 MPH. The theory is that air flow thru the radiator over 20 MPH is sufficient to cool the engine. For those of us who enjoy parading, the fan shroud might help cool the engine at idle and very slow speeds. On the other hand, I wonder if the shroud might restrict air flow thru the radiator at speed. Air passage space is reduced. I think I heard that somewhere. It is interesting that most post Model A cars are equipped with fan shrouds.

Your thoughts on this will be greatly appreciated.

Peyton
 
I've run my 1931 Slant Windshield 4 Door Sedan for 28 years here in S.E. Texas in 100F weather every Summer and have never had any cooling problems. Also have gone to Big Bend National Park and Chihuahuan Desert at 114F outside temperatures and run for days with no cooling problems. Millions of Model A's run without fan shrouds and if your radiator, belt and pump are up to snuff wonder if a shroud is needed.
PS- For parades and slow traffic I run at a fast idle with the spark advanced and keep plenty cool.
 
I run my 30 Tudor in the South Ga summer with no shroud. 60 miles north of Florida line. Haven't had any problems yet. I do have a four blade fan though. Original style water pump. Summer in South Ga, I'm sure, is just as much fun as Jacksonville!!!
 
I think you have a cooling system problem. A Model A with a good properly tuned engine and a well sealed head gasket and a good radiator should not run 190 Deg. on a 80 Deg. day.

I have a thermostat in my car so it will warm up. I just recently returned from a 900 mile trip and the car never got over 180 Deg. even while driving up in the mountains. I live in Southern California and it does get hot here.

My opinion.

Chris W.
 
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I'm with Chris, concerning your coolant temps. It might be time for a thorough clean and flush. Most have good results using white vinegar. A fan shroud will allow the fan to pull more air through the radiator. I believe Henry stopped using them as a production cost saving measure. If the cooling system is in top shape, the shroud isn't required.

Also, both the 8/9N could be fitted with a pusher fan but OEM was a puller.
 
The radiator was re cored not long ago by a reputable radiator shop here in Jacksonville which has re cored radiators for Model A's for years. I flushed the system, filled it with vinegar, and ran the car for over a month this way. At present, the car loses very little water after having been driven 50 or 60 mile in stop and go traffic. It will creep up to 190 and sometimes go to 200 while idling for long periods at traffic lights.
 
Peyton said:
The radiator was re cored not long ago by a reputable radiator shop here in Jacksonville which has re cored radiators for Model A's for years. I flushed the system, filled it with vinegar, and ran the car for over a month this way. At present, the car loses very little water after having been driven 50 or 60 mile in stop and go traffic. It will creep up to 190 and sometimes go to 200 while idling for long periods at traffic lights.
Click to expand...

are you running an original water pump impeller or one of those "clipped" vain ones?

since your radiator is recored - did they put a heavy coat of paint on the fins? thick paint doesnt transfer heat very well.

are the fins tight to the tubes? once again loose or poor contact will have poor heat transfer.

did they recore with the proper thickness core?

fan belt tight?

how do you run your advance lever as you drive? if its set wrong it will cause excess heat or if timing is off

if your car is running lean it will run hotter also

did you do the vinegar before or after radiator recoring? if you did ti after the rust will plug the new tubes and you will loose cooling ability.

lotsa stuff to check.
 
I agree that the shroud will help at idle and low speed, but shouldn't really be needed with a good cooling system. I wouldn't worry about the engine running 190*, as modern cars mostly run in the 200* to 205* range.

Remember, antifreeze not only prevents freeze cracks and rust, but it also raises the boiling point.
 
I did the vinegar treatment before getting the radiator re cored. That might have finished off the old core. The engine is slightly modified with a lightened flywheel and enlarged intake valves?, etc. I drive the car in a lot of stop and go traffic so this might cause the engine to run a little hot. I'll try a shroud and let ya'll know how things turn out. Thanks all!
 
If you are basing your temperatures off one thermometer be sure it is correct. Some of the less expensive add on thermometers can be 15-20 degrees off. Been there, done that!
 
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