The Ford Barn - View Single Post - Are all new 2 blade fans in the catalogs alike?

DougVieyra · 12-07-2016, 09:45 PM

DaWizard: "What is wrong with a 4 blade?"
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The 4-blade fans weigh more than the two blade fans. The extra weight of the 4-blade fan adds extra weight and wear on the shaft of the water pump. Additionally the rivets on the four-blade fan are one more possibility (some say problem) of fan failure.

Some Model A 'technical junkies' have performed tests that suggest that the 4-blade fan produces no more cooling than the stock two-blade fan, and that the two-blade fan is 100% efficient in cooling the Model A engine.

Of course, not everyone agrees with everything; and such is the case in the 4-blade verses 2-blade controversy. You WILL hear 'testimonials' about how much more efficient the 4-blade fan is to the 2-blade fan. But I prefer to defer to both the Ford Motor Company and the 'laboratory' tests that were done by later mechanical engineers who drove Ford Model A's.

That being said, while my stock '28 Phaeton has a Ford-Made two-blade fan (with an inch trimmed off each end, to reduce both weight and centrifugal 'G' force), for my '31 Coupe that has a 'souped up' Touring Engine, I have a six bladed plastic fan with aluminum hub - which some say is sort of a 'belt & suspenders' approach to cooling.

I do have a modern well-made aluminum 2-blade fan on the shelf, just in case I ever need to replace my existing original 2-blade fan.

For me the bottom line after achieving adequate cooling, is reducing weight and stress on shaft of my water pump.

12-07-2016, 09:45 PM	#14
DougVieyra Senior Member Join Date: Sep 2012 Location: Eureka, California Posts: 1,716	Re: Are all new 2 blade fans in the catalogs alike? DaWizard: "What is wrong with a 4 blade?" ------------------------------------------- The 4-blade fans weigh more than the two blade fans. The extra weight of the 4-blade fan adds extra weight and wear on the shaft of the water pump. Additionally the rivets on the four-blade fan are one more possibility (some say problem) of fan failure. Some Model A 'technical junkies' have performed tests that suggest that the 4-blade fan produces no more cooling than the stock two-blade fan, and that the two-blade fan is 100% efficient in cooling the Model A engine. Of course, not everyone agrees with everything; and such is the case in the 4-blade verses 2-blade controversy. You WILL hear 'testimonials' about how much more efficient the 4-blade fan is to the 2-blade fan. But I prefer to defer to both the Ford Motor Company and the 'laboratory' tests that were done by later mechanical engineers who drove Ford Model A's. That being said, while my stock '28 Phaeton has a Ford-Made two-blade fan (with an inch trimmed off each end, to reduce both weight and centrifugal 'G' force), for my '31 Coupe that has a 'souped up' Touring Engine, I have a six bladed plastic fan with aluminum hub - which some say is sort of a 'belt & suspenders' approach to cooling. I do have a modern well-made aluminum 2-blade fan on the shelf, just in case I ever need to replace my existing original 2-blade fan. For me the bottom line after achieving adequate cooling, is reducing weight and stress on shaft of my water pump.