four blade vs. two blade fan

One might mention engine pans will help in cooling, It will funnel the air Thur radiator as for as me I'm a two blade man just love the look :):)
 
Thanks for the advice. I am still quite a ways away from getting to fan selection in my restoration but a two bladed aluminum will go on the list of needs.
 
What about the six bladed plastic fans that the suppliers sell? Anyone have any thoughts about those?

they look anachronistic...even folks who know little to nothing about A's recognize them as plastic, modern and out of place

they do not cool as well as a two blade

they are difficult to remove because of the full diameter circle of blades. Position a 2 blade horizontally and they lift up and out relatively easily

they cost more.
 
I've got the fan shroud, 4 blade fan and engine pans on my mid year '28. NEVER had any overheating in 11 years. I constantly check the fan for cracks or any sign of weakness at the rivets. No issues. Even up a hill, the thermometer gauge barely reads any heating issues.
 
I run my a now with alluminun but still a 2 blades fan, no engine pans and no hood and have never had an overheating problem. I'm still running an original pump but have a very good original never redone radiator.
 
I have a four bladed fan. I think I will install the two blade fan because of the looks. I bought a Brass Works radiator and can run without a fan most of the time. I do not parade the car.
 
I think a simply way to answer the whole 2 vs 4 blade debate is.

The "A" came from the factory with a two blade fan. Over the years the "A" was manufactured did this ever change? The answer is NO which suggests they did not find a problem with the design.

If its not broke, don't fix it.


The design problem makes itself known these days when the fans break and damage sheet metal and radiators when exiting the vehicle.

I am putting a shroud and electric fan on my AA.
 
One might mention engine pans will help in cooling, It will funnel the air Thur radiator as for as me I'm a two blade man just love the look :):)

This whole thing started because I want to switch to a two blade and leak-less water pump. I am not sure if I have a leak-less pump but I thought that worrisome squeal you hear at low speed might be the pump dying. I want to carry a spare water pump just in case. I have shrouds but I never put them back on after the engine removal.

While the engine and is out I thought it would be a good time to switch to the two bladed fan. Like I said I want to switch to the bolts that look like studs and nuts as they are supposed make it possible to remove a water pump without touching the radiator.

Glad to see you are on the right side of the grass.

Amazing the number of posts this topic generated. Did you read the one about the Shay "original 28 Model A" ?
 
ivoryjohn,
I used the bolts you speak of and they work fine for removing the pump without disturbing the radiator, it isn't even necessary to loosen the fan belt, just position the fan crossway's and lower the nose of the pump down, be sure to protect the radiator fins.
 
The four blade fans are known to be getting old and I have heard on this board of them failing much as the original two blade fans do. I replaced my four blade with a two blade aluminum one for that reason, not wanting to hear the ticking bomb finally blast through my hood or radiator.
When I did install the two blade fan I also replaced the studs with those lookalike studs so now, if I have to, I can replace the water pump or fan by just loosening the radiator rods and such instead of pulling or removing the radiator and headlights.
 
The design problem makes itself known these days when the fans break and damage sheet metal and radiators when exiting the vehicle.

I am putting a shroud and electric fan on my AA.


Oh, I was in no way saying use a 2 blade original. I have a modern aluminum 2 blade on the "A".

I'm 100% for electric fans though many would argue it looks very out of place on an "A".
 
I think a simply way to answer the whole 2 vs 4 blade debate is.

The "A" came from the factory with a two blade fan. Over the years the "A" was manufactured did this ever change? The answer is NO which suggests they did not find a problem with the design.

If its not broke, don't fix it.

To continue your theory the two blade fan design used in late 1931 continued through the production of the 1932 four cylinder. In 1933 the fan was redesigned to a four blade that carried a "46" part number. The problem with the design didn't appear until later when rust, fatigue, and people turning the engine over with the fan blade took their toll.

Charlie Stephens
 
The four blade fan was installed in 1934 by dealers for customers that complained about running too hot.
I have not checked it out myself but supposedly on a slow hard pull the four blade fan will move more air, that is; slow engine speed.
I always install a one-piece two blade fan. I advise you to do the same.
A shroud will help more than a four blade fan-and look better.
 
No. The four blade carried a part number that started with "46" and was introduced in 1933.

Charlie Stephens

thanks charlie
a friend of mine is replacing his motor on his AAwhich now has a 4 blade. he told me they came that way. ill correct him and have him get the two blade aluminum.....
mitch
 
The first thing I did when I got my 29' Tudor was to replace the leaking water pump. I got the modern leakless model and I've never looked back. I hold onto the original one in case I ever decide to move toward fine point judging. Anywho, I'm so glad there was a two blade fan on the car when I changed out the water pump because it's so much easier to move the radiator out of the way rather than remove the whole radiator.

Just recently I needed to replaced my fan because of wobble problems and knocking. I went with the aluminum two blade fan from Snyders. Since I'm only an hour away, I went to pick it up. Sitting on the floor of their showroom was a four blade fan with only three blades. (You hate to see that because you know the fourth blade is three inches through some poor guy's hood.) It's perhaps just me, but I feel more comfortable with the two blade fan even though they can quickly become a one blade fan just as fast without proper inspection. I've used the two blade fans and I've never have a problem with the cooling system either.
 
The first thing I did when I got my 29' Tudor was to replace the leaking water pump. I got the modern leakless model and I've never looked back. I hold onto the original one in case I ever decide to move toward fine point judging. Anywho, I'm so glad there was a two blade fan on the car when I changed out the water pump because it's so much easier to move the radiator out of the way rather than remove the whole radiator.

Just recently I needed to replaced my fan because of wobble problems and knocking. I went with the aluminum two blade fan from Snyders. Since I'm only an hour away, I went to pick it up. Sitting on the floor of their showroom was a four blade fan with only three blades. (You hate to see that because you know the fourth blade is three inches through some poor guy's hood.) It's perhaps just me, but I feel more comfortable with the two blade fan even though they can quickly become a one blade fan just as fast without proper inspection. I've used the two blade fans and I've never have a problem with the cooling system either.


The new aluminum two blade fans, for one thing, are eighty years younger, and apparently can survive the "working" that blades do over the years. Please tell me in eighty years if it survived.:D
 
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