Were 4-blade fans ever an original ftting?
 

Were 4-blade fans ever an original fitting on Ford As, or were the original fans always 2-blade?

Re: Were 4-blade fans ever an original ftting?
 

FAN and FAN BELT
Only two basic types of fans were used during
the Model A Ford production. The first, used
throughout production, was a steel, two-bladed,
double thickness propeller type manufactured by
Ford. In late July 1930, an engineering drawing was
released for the production of a single thickness
fan blade to be produced by Holley with a large
radius. In late 1930, the single thickness fan blade
was redesigned so that the large radius was
eliminated. This latter fan blade
was also used through the end of production. The
7 / 16"-20 (29 / 64" x 5/ 8") castle nut securing the fan
to the water pump shaft was black enamel. Castle
nuts had rounded grooves in 1928-1929 and castle
nuts with square cut grooves began appearing in
1930 and by 1931 were predominantly used.

Re: Were 4-blade fans ever an original ftting?
 

I think the 4 blade fan was used on trucks. They can break blades like a 2 blade but it's not as common.

Re: Were 4-blade fans ever an original ftting?
 

None of the original propeller type fans have good fatigue life, and are prone to cracking. The fan blades see a combination of fore-aft bending and centrifugal tension loads that the sheet metal Ford & Holley designs are poorly designed to carry.

I installed a NOS Holley single thickness fan on my Coupe after its existing Ford fan cracked. The single thickness fan also cracked in less than 20,000 miles.

The cast aluminum reproductions fan, because of its homogeneous casting, is far superior to the original fans.

Re: Were 4-blade fans ever an original ftting?
 

Trucks did not come with 4 blade fans. That is an old wife's tale. The 4 blade fan was after model A production, and probably bought at western auto,or sears.

Re: Were 4-blade fans ever an original ftting?
 

The 4 blade fan most often seen on Model A's was from the 4 cylinder 1933-34 and carried part number 46-8600. The '32 4 cylinder used the '31 Model A fan. This fan became the dealer replacement fan for '28 through '34 when it was introduced and can be found as such in the Green Bible. This explains why they are seen so frequently compared to the number of 4 cylinder cars produced in 1933-34. Of course there was the cheap auto parts stores 4 blade fans and later cheap reproductions. Although not as common these fans fail also which would make me use a current aluminum reproduction if given the choice. I say current because some of the early aluminum fans had quality problems. I think most of these failures occur because people have in the past turned the engine over using the fan blade. Once a crack starts it grows with time.

Charlie Stephens

Re: Were 4-blade fans ever an original ftting?
 

Mike; What do you mean by "large radius" ? Jack