4 or 6

[2speed]

Four or six bladed fan? I need more cooling. 2 blade is not enough, I don't care what Henry did.


Preferences? Evidence based opinions?


I want to try the fan first, before a shroud possibility.

[alexiskai]

Above 35 mph the fan does nothing, regardless of the number of blades. If you’re overheating while driving, the fan won’t help you. If you’re overheating while going slow, I.e. in a parade, I think the 6-blade fan moves more air at low speed but I might be misremembering that.

[Dick M]

I run a 2 blade fan and have no cooling problems. I live in a 90-100 degree area in the summer. I installed a re-cored radiator about 10 years ago. My car never goes over 180 degrees..

I had nothing but cooling problems prior to installation. I would not want you to chase a remedy that will not work...

I would check the condition of your radiator. The tubes could be plugged up.

You could also have scale built up in your block. A good block cleaner will fix this problem.

Best of luck!

[Vic in E-TN]

Blade/fan performance is characterized by the following:
1. Angle of blades.
2. Speed of blades
3. Length of blades.
4. Number of blades.
As you can see from other comments that 2 blades that are designed as originally are good for cooling performance in many conditions, . You should find what the problems are first. I just wrote a small article for our club Rumble Seat Reviewer that outlined how to use an infra red thermal tool from Harbor Freight to check out your radiator temperatures before you do anything else.


Vic

[Zax40]

I have one for sale in the swap meet section if you really just want a fan with more blades

https://www.fordbarn.com/forum/showthread.php?t=348420

[AzBob]

Sponsored Links (Register now to hide all advertisements)

As others have pointed out, With a good radiator and a clean block a 2 blade fan will be more than sufficient. I even have a Stipe fan speed reducing pulley on my ’30 sport coupe.

We have hot temperatures here in AZ during the summer and have had no overheating issues.

I even ran my 1926 Model T without a fan for sometime with no overheating.

[Big hammer]

Originally Posted by 2speed

Four or six bladed fan? I need more cooling. 2 blade is not enough, I don't care what Henry did.


Preferences? Evidence based opinions?


I want to try the fan first, before a shroud possibility.

H2O with antirust and pump lub will run 20-30 *F cooler than antifreeze, above 35 mph and fans slow the airflow through the radiator so that’s maybe why Ford went with the 2 bladed fans . Doing a good chemical flush of the cooling system would be what I would do first.

[Y-Blockhead]

Originally Posted by Big hammer

H2O with antirust and pump lub will run 20-30 *F cooler than antifreeze, above 35 mph and fans slow the airflow through the radiator so that’s maybe why Ford went with the 2 bladed fans . Doing a good chemical flush of the cooling system would be what I would do first.

If that is true, it is a good thing I run Anti-freeze in my Town Sedan, otherwise it would be running 135°F, which is too cold for my liking.

A thing a lot of people don't realize is anti-freeze also raises the boiling point of the coolant.

What kind of oil is best again??

[TMarsh]

More blades is not the answer. I live in Texas and drive my A regurlarly. In town and on the highway. I have a two blade fan and good radiator. A is stock with the exception of .80 over engine. Going to be triple digits today, to hot for me but not my A. Listen to the answers you get before you spend money throwing at a problem. I agree with the earlier posts Harbor Freight infrared temp checker to start. I also have a 165 thermostat and never get above 180.

[WHN]

As others have said, you have other problems besides your fan.

I would look at your radiator first. Than flush out your engine block.

Remember, like the Model T, the Model A is designed with a syphon cooling system. 32 gallons per minute if every thing is clean. The radiator being the most important part.

Take the bottom hose off your radiator, cover opening with duct tape.fill radiator with water now remove tape. Radiator should drain completely in a couple of seconds. If not you have a problem.

Leave radiator cap off. Good luck.

[2speed]

Clean block, actually the cleanest block you can have. Radiator was cleaned and repaired, original.


60/40 antifreeze solution. Engine pans are in place. Have a license plate because it's law.


Running a temperature gauge in the neck.


Have a thermostat with the thermostat knocked out, so a 1 inchish hole to slow the water down. Before knocking the thermostat out, car would overheat on hills easily.


Climbing hills at 7,000+ feet on 100 degree days is tough, to the point of pulling over and waiting.


50mph on 100 degree days is running between 185 and 190. Car is loaded pretty well. When it's 80 degrees out car will run 5-10 degrees cooler.


While this was stationary tests: https://www.tulsamodelafordclub.com/...-fan-air-flow/


4 blade is significantly more air. There is another article out there from years ago, but the scan is too small to read by Ed Rossig.


If you have a wind perpendicular to or behind the car, the air flow through the radiator might not be the "doesn't matter above 35mph" that you think it is.

[WHN]

Originally Posted by 2speed

Clean block, actually the cleanest block you can have. Radiator was cleaned and repaired, original.


60/40 antifreeze solution. Engine pans are in place. Have a license plate because it's law.


Running a temperature gauge in the neck.


Have a thermostat with the thermostat knocked out, so a 1 inchish hole to slow the water down. Before knocking the thermostat out, car would overheat on hills easily.


Climbing hills at 7,000+ feet on 100 degree days is tough, to the point of pulling over and waiting.


50mph on 100 degree days is running between 185 and 190. Car is loaded pretty well. When it's 80 degrees out car will run 5-10 degrees cooler.


While this was stationary tests: https://www.tulsamodelafordclub.com/...-fan-air-flow/


4 blade is significantly more air. There is another article out there from years ago, but the scan is too small to read by Ed Rossig.


If you have a wind perpendicular to or behind the car, the air flow through the radiator might not be the "doesn't matter above 35mph" that you think it is.

Why do you want to slow the water down? If you’re running hot, you need more flow.

Am I missing something here.

[BRENT in 10-uh-C]

Originally Posted by 2speed

Clean block, actually the cleanest block you can have. Radiator was cleaned and repaired, original.


60/40 antifreeze solution. Engine pans are in place. Have a license plate because it's law.

Running a temperature gauge in the neck.

Have a thermostat with the thermostat knocked out, so a 1 inchish hole to slow the water down. Before knocking the thermostat out, car would overheat on hills easily.

Climbing hills at 7,000+ feet on 100 degree days is tough, to the point of pulling over and waiting.

50mph on 100 degree days is running between 185 and 190. Car is loaded pretty well. When it's 80 degrees out car will run 5-10 degrees cooler.

While this was stationary tests: https://www.tulsamodelafordclub.com/...-fan-air-flow/

4 blade is significantly more air. There is another article out there from years ago, but the scan is too small to read by Ed Rossig.

If you have a wind perpendicular to or behind the car, the air flow through the radiator might not be the "doesn't matter above 35mph" that you think it is.

From my vantage point, it sounds like your mind is made up, -and that is OK because it is your car and you are free to do it your way. I will offer my thoughts for others who might be lurking and to help with clarifying information...


FWIW, using an Antifreeze coolant mix in a Model-A radiator generally provides less cooling efficiency when compared to using straight water because the cooling system it is not under pressure. Slowing the water down is a controversial topic since generally speaking, most agree the only real benefit to slower water flow was when the radiator tubes were plugged and the coolant could not drain thru the tubes as fast as the pump was pushing it into the upper tank. Even a 2 row Model-A radiator can flow more water than a stock pump can move. Temperature gauges have been known to not be accurate, -especially if the sender is mounted in the water outlet neck. The reason(s) are more than I care to write but coolant is almost never fully filling the outlet neck (above the impellers) because there is not enough head pressure generated in the radiator tubes to force it full. Additionally, the design of the water pump impeller causes cavitation and air pockets as it is moving coolant. Therefore, when water is intermittently surrounding the temperature sender, the readings will be skewed.

It has been my experiences that a thermostat in the typical Model-A application generally offers negligible increases from a performance perspective, ...especially in higher ambient temperatures. The aftermarket Thermostats are most effective when the A engine is being operated in colder temps because it raises combustion temps by not allowing the engine heat to be dissipated.

With regard to perpendicular or aft-flowing air, it really does not matter what the wind direction is. If the vehicle is traveling forward at much more than 15mph, the frontal area against the radiator core will flow enough wind to allow the heat to dissipate. The radiator should be able to dissipate the heat no matter if there is a frontal wind of 15mph -or 60mph.

[Synchro909]

Originally Posted by 2speed

Clean block, actually the cleanest block you can have. Radiator was cleaned and repaired, original.


60/40 antifreeze solution. Engine pans are in place. Have a license plate because it's law.


Running a temperature gauge in the neck.


Have a thermostat with the thermostat knocked out, so a 1 inchish hole to slow the water down. Before knocking the thermostat out, car would overheat on hills easily.


Climbing hills at 7,000+ feet on 100 degree days is tough, to the point of pulling over and waiting.


50mph on 100 degree days is running between 185 and 190. Car is loaded pretty well. When it's 80 degrees out car will run 5-10 degrees cooler.


While this was stationary tests: https://www.tulsamodelafordclub.com/...-fan-air-flow/


4 blade is significantly more air. There is another article out there from years ago, but the scan is too small to read by Ed Rossig.


If you have a wind perpendicular to or behind the car, the air flow through the radiator might not be the "doesn't matter above 35mph" that you think it is.

Why on earth would you want to slow down the water??? I have never seen a problem corrected by reducing the efficiency of one of the components.

[Keith True]

If you speed the water flow up too much it drops down through the core,then back to the block without transferring it's heat.If you shoot the heat number at the top of the core while running,then the bottom of the core while running,there should be a substantial difference in temperature.If the temp difference isn't a lot,then the water is running through it too fast,or the radiator still isn't working right,new or old.

[WHN]

Originally Posted by Keith True

If you speed the water flow up too much it drops down through the core,then back to the block without transferring it's heat.If you shoot the heat number at the top of the core while running,then the bottom of the core while running,there should be a substantial difference in temperature.If the temp difference isn't a lot,then the water is running through it too fast,or the radiator still isn't working right,new or old.

Keith, the way I have read his thread, he is slowing the water down with the one inch restriction.

The syphon flow is what it is. Any restrictions will result in less flow. The water pump is marginally effective.

Design is for up to 32 gallons per minute.

Great question.

[Dan McEachern]

Be aware that often with old original radiators, the fins don't make good contact with the tubes and can't transfer the heat. There is no fix for this other than a new radiator or core. Its a common problem with old radiators- just throwing that out there . Hopefully this is not the OP's problem, but.......

[2speed]

In terms of my mind being made up, I just want proof, not "Mine's never overheated so....".


I've watched the temp gauge bounce, which is from the cavitation,etc like you say, but it will average at the numbers I say. I've also seen the temp gauge bounce due to wind being front, back, or side.


It freezes where I live, and I don't have time to drain, refill, drain, refill with different coolants depending on where I want to drive or what weather pattern is coming.


I literally posted a link that shows that a 4 blade fan pulls more air. Is the study wrong? Is there a different study that shows different?


When pulling a hill, the engine RPM is high, but ground speed is low, well below 35 mph. The 4/6 blade fan would be better right?


Would a shroud be more effective than a multi blade fan?


Water flow capacity through the radiator is not the same as heat disappation.

[WHN]

Originally Posted by 2speed

In terms of my mind being made up, I just want proof, not "Mine's never overheated so....".


I've watched the temp gauge bounce, which is from the cavitation,etc like you say, but it will average at the numbers I say. I've also seen the temp gauge bounce due to wind being front, back, or side.


It freezes where I live, and I don't have time to drain, refill, drain, refill with different coolants depending on where I want to drive or what weather pattern is coming.


I literally posted a link that shows that a 4 blade fan pulls more air. Is the study wrong? Is there a different study that shows different?


When pulling a hill, the engine RPM is high, but ground speed is low, well below 35 mph. The 4/6 blade fan would be better right?


Would a shroud be more effective than a multi blade fan?


Water flow capacity through the radiator is not the same as heat disappation.

If you really have the flow of coolant through your radiator that is required and it’s still overheating. You have a radiator problem.

Have you checked the timing?

These are really simple cars. A good radiator is a must. That’s what dissipates the heat. You need the flow to get the heat to your radiator. A good radiator might actually allow your engine to run cooler than you might think it should.

My last post. Good luck.

[mcgarrett]

Seems to me Brent & Dan are right on target with their comments. I live in Texas, which is synonymous with HIGH summer temperatures. I had a cooling problem much like the OP had and found my original radiator was causing most of the trouble (clean radiator or not) due to fins not making good contact with the tubes. I tried both 2 blade and 4 blade fans to no avail. I then replaced the radiator with new Brassworks unit and temperatures were back under control.

Here are some suggestions of things to check if you haven't already...

1) Check for bubbles in the coolant when the engine is running (remove radiator cap and observe). If you notice bubbles it's a pretty good indication of a blown head gasket.

2) Remove the restriction or thermostat from the upper hose (they were NEVER installed at the factory for any reason I know of) it will not help with cooling.

3). After driving in hot weather long enough to get the engine temperature up, shut the car down and listen for any signs of boiling, gurgling. or steam coming from the engine. If the coolant is at the proper level check to see if any is coming out of the overflow tube. If the radiator is spitting water on the ground your coolant level is too high or you are overheating due to a radiator that has exceeded its service life - or perhaps suffering with issues found in points 1 & 2 above.

4) Replace the anti-freeze/water mixture with 100% water and a corrosion inhibitor additive like Water Wetter or 40 Below. For winter driving, switch the coolant mixture back to 50/50 antifreeze and water.