2 Blade Alum. Fan

C

callcoy

Senior Member
This is not a discussion of the pros and cons of employing a Alum. fan on your or my Model A. I will be using this non-standard fan in an effort to have a durable and safe fan, I do not have a car (truck) that will ever be a points vehicle while I own it, not that I don't envy those vehicles that are.

While doing mock up on my "mule engine" I discovered a problem and wonder if others have had the same finding. Using a straight edge off the crank pulley, the Alum. fan is offset to the rear of the engine by 3/16th's of an inch. When the original steel fan is placed on the pump shaft the pulley lines up correctly. I have tried switching water pumps and had the same results, the Alum. fan sits too far back.

My question to the "Barners" is have any of you experienced what I have described?
 
I have three and no problems like what you describe. However, in the past there have been problems with many repro fans having the taper mis machined. The early aluminum fans had problems with blades out of line and balance. That had been thought to have been corrected. But with every new batch, new problems can arise.

If you bought it from a reputable supplier, call them and discuss it. If its a common problem they would know first. Most of them will replace any item you are not pleased with.
 
I had to grind a little off the nose of the pump casting to get my aluminum fan to fit, but does line up.
 
The fellow who bought my coupe called me up one day and told me that he had
decided to put an aluminum fan blade on since he was going to remove the old one
in order to install the new water pump I had provided with the car. He then told me
that he couldn't get clearance to put the new blade on. When I asked him why he
had decided to replace a perfectly good steel blade with the aluminum one he stated
that his friends thought "It was the right thing to do." After I gave him my usual
"If it ain't broke, don't fix it" speech he decided to put the original one back on. Since you didn't ask for any pro/con discussion, I won't offer any, but I will just simply say
that with all of the many non stock vendors, you're going to get many different standards of quality. Good luck.

Jack
 
Jack '29 Sport Coupe said:
... When I asked him why he
had decided to replace a perfectly good steel blade with the aluminum one he stated that his friends thought "It was the right thing to do." After I gave him my usual "If it ain't broke, don't fix it" speech he decided to put the original one back on. ...
Click to expand...

Jack, et al.,

Not to start an argument, I hope, but here's why many would say it's the right thing to do--if it ain't broke, it will be. Eighty years of vibration/stress have to take a toll.

2010parts008.jpg


Steve
 
I just took my aluminum fan blade off and replaced it with a steel replacement blade that was sold back in the 50's I got it at a swap meet or Ebay I am not sure which ...Anyway I notice less vibration with the steel fan AND when I removed the aluminum one I could see looking down into the shaft hole that the tapered hole in the fan does NOT match up with the water pump shaft the contact area was quite visible and extended only a short distance down the taper in the fan ...The aluminum fans tend to loosen up too on the shaft due to the soft material and should be inspected often ...The fan I replaced it with is a two blade one of the same construction as the 4 blade fans used on the trucks the truck fans are good ones ...Another fan that is good is the plastic fan one of the guys in the club has the plastic fan and says it has been trouble free ...They sell the plastic one at Snyders ... :)
 
During a return trip from the Oklahoma Centinneal Parade in 2007, my friend after just finishing a beautiful fine point resoration of a 29 phaeton (3 years) with the original 2 blade steel fan was more than surprised when half of the fan ripped through the top of the hood. The other half through the radiator. I would love to see a quality steel 2 blade fan that would hold up just for appearance. Until then I agree with Steve.
 
B0B said:
I just took my aluminum fan blade off and replaced it with a steel replacement blade that was sold back in the 50's I got it at a swap meet or Ebay I am not sure which ...Anyway I notice less vibration with the steel fan AND when I removed the aluminum one I could see looking down into the shaft hole that the tapered hole in the fan does NOT match up with the water pump shaft the contact area was quite visible and extended only a short distance down the taper in the fan ...The aluminum fans tend to loosen up too on the shaft due to the soft material and should be inspected often ...The fan I replaced it with is a two blade one of the same construction as the 4 blade fans used on the trucks the truck fans are good ones ...Another fan that is good is the plastic fan one of the guys in the club has the plastic fan and says it has been trouble free ...They sell the plastic one at Snyders ... :)
Click to expand...

Sorry for being so negative, but you may not be out of the woods with the four-blade. The repro's can come apart, like this one did.

2010TroyRoundup002.jpg


When I posted this photo before, someone opined that this might not have happened if the person had not been using an alternator requiring a tighter belt--maybe so. Also, the original four-blades are not necessarily reliable; I know for a fact that they can be pre-stressed from amateur mechanics over the decades torquing on them to fine tune the points' closure during tuneups, then noticing that it looks a little bent, then trying to bend it back until it looks about right--pretty much with every tuneup.

I use plastic.

Steve
 
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I lost a blade off of a two blade steel fan. It took out the top of my hood, ruined my radiator and it tore half of my water pump off of the head. It was one loud bang and it scared the hell out of me. Before that had happened, the steel fan looked good the last time that I had inspected it. I have since replaced it with an aluminum two bladed fan and with a new greaseless water pump. The fan now looks and runs perfect. The new aluminum fan lines up perfectly with the other pullys. I purchase the modern water pump and fan from Mac's. If your new fan doesn't fit properly, exchange it for one that will fit properly. Everything is not perfect in this world.
 
I appreciate the input, comments and horror stories about fans. I should have noted that the only other fan I own is a very very bad steel stock unit with rust "lace" near the hub, you can strain pasta with this. It is also cut off at the outer ends, this is a great example why these can fly apart from internal rust. I am going to elevate the front of the engine, it is sitting on the front pulley, then check the end play of the crank. I doubt it has that much end play, besides everything lines up with the steel fan.
 
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