6 Bladed fan
 

I am considering obtaining a 6 bladed fan for my 1939 Pickup. It seems to run a little warm and just wondered if a 6 bladed fan would cool the engine just a little more. When I searched for the 6 bladed fan, the pictures seem to indicate that one of the blades is longer than the other 5. I would think that this could create and imbalance and wondered if anyone has experience with the 6 bladed fan, the longer blade, and does it help cool the flathead.

Re: 6 Bladed fan
 

I changed to a 6 blade on my truck,did not seem to help on cooling and is just a tad noisier.This is on a 1952 F-1 239 flathead 8RT.

Re: 6 Bladed fan
 

Six bladed fans were used on large trucks. They are noisier, as mentioned above. The stock fan should be adequate if your radiator is clean inside and out. This is the main reason for overheating in the majority of cases. Good radiator shops are scarce, and it is the often better to replace rather than try to fix the old one. The fins often separate from the tubes, and an interior coating of lime the thickness of a coat of paint will reduce the efficiency by half in some case.

Re: 6 Bladed fan
 

The 6 blade fans have 3 short blades and 3 long blades. I have one and still have heat issues.

Re: 6 Bladed fan
 

It gets pretty darn hot in Glendive though!

Re: 6 Bladed fan
 

...... as can clearly be seen on this fan if you look at every OTHER blade (10, 2 & 6). DD


https://www.fordbarn.com/forum/attac...6&d=1636843499

Re: 6 Bladed fan
 

the varying of blade length was done to reduce noise [even numbers of even length blades tend to drone]

Re: 6 Bladed fan
 

Thank you all for your comments. I had my radiator completely rebuilt and was looking for possibilities to lower the running temperature. Sounds like the 6 bladed fan doesn't do much other than add noise. I have some water pumps that I am planning on sending to Skip. I am not in a hurry now that it is coming up on winter, but Skip mentioned that winter is a good time to send him items for rebuild. Thanks again for your comments

Re: 6 Bladed fan
 

Skips water pumps helped mine quite a bit. Money well spent.

Re: 6 Bladed fan
 

ktgarcia, Do you have a generator mounted fan? The one pictured by V8coopman is a crank mounted fan.

Re: 6 Bladed fan
 

there are also different diameter generator pulleys that can be used to optiize fan and charging for either slow or fast driving

Re: 6 Bladed fan
 

Another thing to consider would be an original fan shroud that were used on the big trucks during this era. I have one on my '39 pickup and it really directs the air through the radiator. If your set-up has the generator mounted fan it might help.

Re: 6 Bladed fan
 

Trucks didn't go very fast as a general rule and they worked harder to pull heavier loads. Cars can cool down pretty well at roads speeds but trucks have to rely on the engine rpm more to draw air through the radiator.

A passenger car or light commercial vehicle should not need a big multi blade fan like that to cool. If it does then it may have radiator tube blockage, a coolant leak, or an engine problem that is adversely affecting it's cooling system.

Re: 6 Bladed fan
 

I noticed on my 52 Merc(omatic) there are a lot more blades than on the 53 which has a standard transmission. The 53 is a non runner so I can't comment on which cools better. The fact that the 53 had a trailer hitch on it would indicate it must have worked hard occasionally and still got by with only a few blades on the fan.

Re: 6 Bladed fan
 

Thanks to all that replied.
Deuce Lover: My fan is off the generator.
Gary U: Do you have a picture of the shroud you mentioned?
HD Rider: I am planning on sending off my extra water pumps. Do you have
any tips on changing them out once I receive them back from Skip? I have to
raise the front of the motor to change the water pumps.
Kurt in NJ: I didn't know about diameter of pulleys. Do you have any
information on what the diameters are best?
Ralph G: Thanks for the input. I still may look into a 6 bladed fan.
Aussie Merc: Did you notice a difference in noise with a 6 bladed fan?

Thanks again for all that replied. I have many things to consider over the winter.

Re: 6 Bladed fan
 

I put a 6 blade fan on a chevy with a 235 once. It sucked the power right out of it so I took it off the next day. It felt like I had the emergency brake on, that's how bad it was

Re: 6 Bladed fan
 

First, is the pickup actually running warm? The stock temperature gauge reads 3/4 hot at 180 F, which is normal operating temperature.


If it is running warm, is it hot at idle or when running down the road at speed? Usually it is only one or the other.
Hot at idle means not enough water flow and/or not enough air flow. Six blade fans help when running warm at idle but nice and cool down the road.
Hot running down the road means your radiator isn't keeping up. More fan blades are actually just more blockage for air at higher speed and won't help at all when running down the road. The same is true for shrouds.

Re: 6 Bladed fan
 

When changing the water pumps, I supported the engine with a block of wood wrapped in an old towel and a floor jack. The old towel was to protect the paint on the oil pan since I put a lot of time and effort into making it as correct as my limited talent allows.

Re: 6 Bladed fan
 

I just looked at my fan, not installed yet but came with the truck, and it's a 6 blade, all same length. I'll post if a pic if anyone is interested.

Cheers

Re: 6 Bladed fan
 

And I have one with riveted on aluminum blades. Maybe from a military V8 welder I once had. Let me know if you want it.