4 Blade fan

colin1928

colin1928

Well-known member
G/Day I have read here many times of the cast 2 blade fans cracking and breaking I have had this happen myself many years ago damage +
And have just read of another
Question do the original steel 4 blade engine fans have the same problems
can I keep my old 4 blade or should I change it?
Thanks Colin
 
There were no model A 4 blade fans but yes even the 4 blade fans that were used in 1933 and beyond as a replacement for A and B engines will shed blades. I happened to me.
 
In 1950, my dad bought a '31 AA280A that later in life became my first vehicle. It had 10,000 miles on it when he bought it and it had a 4-blade "truck" fan on it as well as the heavier truck radiator. I would be hard pressed to think that with only 10K miles on it in 20 years that much of anything was changed from the way it came from the factory, especially the fan of all things.
 
I have checked and can not find any cracks
this is in my Australian RHD pick up almost all the commercial A models I have seen here are 4 Blade with the HD radiator
 
I Had the same problem with the repro cast iron one took out the rad and the water pump !!!

I would rather use the original truck 4 blade fan at least it was made by Ford .

Just keep checking for cracks.or buy one of the Ally 2 blades.

John Cochran
 
This intrigues me cause I've got two of them (Stamped 4 blade fans)and the steel is liiiiight! (16 gauge) Later (50s 60s) were made out of heavier stuff, (12 gauge, I think) Mower blades are better steel (1/8 or better) and do much more, but similar work, under much worse conditions and don't break, well not often anyway. Why can't/shouldn't we adapt the later fans to our cars just for the safety aspect alone? Any comments? Sorry, I didn't mean to hijack the thread, only expand the discussion.
Terry
 
Here's what happened to a friend's repro 4-blade fan. Of course, everyone says he had the belt too tight. Maybe so, maybe not, but I've only ever seen this with a repro.

I used a truck 4 blade for many years with no problems. What scared me into changing, when I came to my senses, was recalling all the times I had bent one of the blades, and then bent it back until it looked about right, while I was reefing on it to find TDC with the timing pin. What are the chances that no one else has done that in the 80 some years of your fan's history?

Steve


 
I had a four blade break last Easter Sunday when I was out for a spin. The blade broke off and went through the rad. Luckily it did not cause any other damage, like to the hood etc. I would not use anything other than the cast aluminium two blade fan or the plastic six blade fan.
 
The 1933 and later model 46 type four cylinder truck fans were solt as replacements for the model A after the original steel model A two blade propeller type fan was no longer made. These four blade fans had the blades riveted to the hub and pulley. These fans are known for the blades cracking in the narrow area between the rivets. Most of my model A's had the four blade fans when I got them. I've had two of the four blade fans sling a blade and consider myself lucky not have been hit by the flying blades. I've had one of the original two blade fans sling a blade. I consider all of the old fans to be unsafe. I have used the Snyders cast aluminum repro two blade fans since the seventies with great service. I consider the Snyder aluminum fans safe and they look original. I suppose that anything is possible but I've never seen one fail. I keep these old fans for decorators.

2177398-T400300.jpg
 
Thank you gents I will be changing asap
I always belived 4 blades were safe as never heard of a bad 1 but thanks to those whom posted it will be changed NOW
 
It has been fifty years since I was involved with this issue, but something that was done in the '50's & '60's, was to find an excellent original Ford-Made two-blade fan and cut 1" off the end of the blade. This did not reduce the efficiency of the air-pull or reduce the efficiency of the cooling. But what it did do, was reduce the weight of the fan and reduced some of the centrifugal 'G' force at the end of the blades. After the fan blades were cut down (1" on each blade) the fan was then spun balanced, filing off metal on the heavy end, to get a perfect balance.

While this amendment certainly did not guarantee a trouble-free fan, with the reduced 'G' force, it did significantly reduce the probability of a blade flying off. Also, with the reduced weight and reduced 'G' force, it also helped reduce wear on the impeller shaft.

A side note about the two-blade fan verses the four-blade fan - a side benefit of a two-blade fan blade, was the easier removal / work on the water-pump - with the radiator not needing to be fully removed from the car.

While I still have this original cut-down blade on my original '28 Phaeton, I have up-dated this idea on my late '31 Dlx. Coupe with the modern six-blade "composite plastic" fan with aluminum hub.
 
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I shortened this aluminum repro fan 3/4 inch on each blade. The reason that I shortened it was because it was just touching the upper edge of the upper hose. The cause was the repro radiator upper neck was angled a little bit off . Shortening the blades was the easiest fix. It cools good and the shorter blades don't take as much horsepower !!! smiley face. Couldn't resist painting it red.
Sept.jpg
 
The 4 blade on my A is very nice and works well. EXCEPT the "red rust" seeping out from where the 2 pieces (actually 3, counting the pulley) are riveted together. A new 2 blade aluminum is on my workbench ready to replace the now questionable 4 blade. The reason I chimed in here is the the fan looks to be fine or it wouldn't have been on the A in the first place. But, then on inspection one day I spotted the rust, which at least to my mind means the thing is on the path to destruction. Makes me wonder how many other seemingly fine 4 blades are out there rusting away from the inside out along the mating surfaces where the eye cannot see.
 
Well, my four bladed fan was not riveted together, four hex bolts (5/16?) holding the blades to the hub. I didn't like the looks of it so removed one blade. So far so good and the engine runs very smoothly. Am I asking for trouble down the road?

Sewall Tyler
 
I been running 1/2 of a 4 blade fan for 9 years and no problem. I keep a close eye on it though. Was on the car when I bought it. I have a Snyders repop on hold for it.
 
There are a hundred fixes for this problem.
Most involve changing the stock look. Most will work ok.
I chose to buy a racing fan guaranteed for 10000 rpm.
 
Quigley1930 said:
Well, my four bladed fan was not riveted together, four hex bolts (5/16?) holding the blades to the hub. I didn't like the looks of it so removed one blade. So far so good and the engine runs very smoothly. Am I asking for trouble down the road?

Sewall Tyler
Click to expand...

I've run that style fan before. I think mine came from Warshawsky or JC whitney. Some of the fans like that had a steel hub and pulley and were pretty good fans. Others had an aluminum or some type alloy hub and pulley that often failed at the key way. when this happened the hub would get loose and wobley. I've never had one of that style sling a blade. I consider it safer than the old model 46 fans that were sold as replacements for the model A.
 
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