Another Original 2-Blade Fan Takes Its Toll

[Marco Tahtaras]

I usually hang on your every word, Marco, but I don't understand your eyeglass prescription analogy--nor your apparent disdain for Magnaflux, which is a proven method of detecting cracks that are otherwise invisible.

Magnaflux has it's place for sure. I just don't see the advantage with clean, smooth sheetmetal. Maybe I'm missing something here?

Again, I'm not suggesting anyone else run one. I was however trying to explain that it's not just basic use over 80 years that makes one prone to failure, but other factors that are generally identifiable but nearly always overlooked. True, one example only proves the potential of an original fan in equal condition. The trick or art is identifying that condition.

BTW, I spin mine MUCH faster than most. I do monitor it for surprises but don't really expect any.

[Bill Goddard]

OK. Time for my 2 cents - maybe 1 cent. What would the group think of a life limit on fan blades. Maybe 5000 miles. Helicopter rotors are limited by max no. of hours because of the alternating flex problem. I would think you could get 5000 miles on a NEWLY manufactured fan.
Also - if the new sheet metal fans are formed at the base with a shearing burr on the outside radius of the curve there is a real possibility of a crack developing along that edge. I would check a new blade for this burr and file and polish the edge real smooth if I found one.

[MikeK]

Originally Posted by Bill Goddard

OK. Time for my 2 cents - maybe 1 cent. What would the group think of a life limit on fan blades. Maybe 5000 miles. Helicopter rotors are limited by max no. of hours because of the alternating flex problem. I would think you could get 5000 miles on a NEWLY manufactured fan.
Also - if the new sheet metal fans are formed at the base with a shearing burr on the outside radius of the curve there is a real possibility of a crack developing along that edge. I would check a new blade for this burr and file and polish the edge real smooth if I found one.

Bill,
You want Model A guys to throw something away that ain't broke yet?

They won't replace 30 year old tires 'till they blow, you want them to throw away a $200-$300 fan! By the way, I agree with you!

[BRENT in 10-uh-C]

Originally Posted by mikek

bill,
you want model a guys to throw something away that ain't broke yet?

they won't replace 30 year old tires 'till they blow, you want them to throw away a $200-$300 fan! by the way, i agree with you!

classic!!!

[RockHillWill]

Just adding a thought or twwo on this subject. I hang around some of the fine point crowd for the knowledge and most importantly I have an appreciation for the preservation of history. My limited knowledge leaves me with the impression that Henry Ford was a leader in the industrial evalution (sp?) that lead to the greatness of this country, and I like the fact that the Restoration Guidelines and Judging Standards does the most nice job of revealing the details of that history. I further believe that these standards should not be 'stepped downwards' to make it easier for compliance. I used to argue this point somewhat with Marco, but his steadfast adhesion to this approach has made me a believer in 'right is right'. I used to hang around some of the race car folks, and on any given Sunday if you were able to make the race you could take pride in your accomplishments. If you missed the race you went home and worked harder, you did not petition NASCAR to 'dumb down the rules' so you could be more competetive. So much for my soapbox perspective regarding rules changes. I had a friend that has since passed away that was able to restore the original fans in a manner that seemed to be quite well done. He would never share how he did it, but was adament about removing the rust from inside the fan. I was able to use a ball micrometer and check the fan in any area and it would be a very consistant measurement. I am familiar with magnafluxing, but he made me understand that it only checks cracks that are on the outside of the fan, not those on the inside. If I understood him correctly he was hinting that whatever made the rust form on the inside was not visable from the outside and that centrifigal force would move the rust on the inside, outward and impact the balance, and depending on the final resting place of the rust accumulation, it would determine how the blade was twisted and the resulting crack to appear. He was some how able to remove that rust on the inside(???????), balance the fan, and have it provide a long lasting life. He had a Tudor that have 42,000 + touring miles and his close friend has a Phaeton that has more than 46,000 miles and it is still used on touring. Again, just an old mans thoughts!

[Michael P.]

Sponsored Links (Register now to hide all advertisements)

To the fellows that asked about the 4 blade repro fans. When I restored my '31 Slant Windshield 4 Door Sedan (160-A) 23 years ago I was concerned about the reports of the 2 bladed originals comming apart so at the time opted to buy a 4 bladed repro. Being a bit paranoid I took the new 4 bladed fan and spot welded over the rivits and also ran a small smooth bead at every seam where the blades overlapped. I then ground the longer welds smooth, ground the welds at the rivits a smooth domed shape and painted where one cannot even see the welds. I am an amatuer home welder and do not have technical engineering training but the fan has worked well for the past 23 years as I assume a "single" unit due to the welding. Maybe someone with better technical know how will chime in to let us know whether the welding on my part is really ok to do or pure overkill!

[MikeK]

Originally Posted by Michael P.

To the fellows that asked about the 4 blade repro fans. When I restored my '31 Slant Windshield 4 Door Sedan (160-A) 23 years ago I was concerned about the reports of the 2 bladed originals comming apart so at the time opted to buy a 4 bladed repro. Being a bit paranoid I took the new 4 bladed fan and spot welded over the rivits and also ran a small smooth bead at every seam where the blades overlapped. I then ground the longer welds smooth, ground the welds at the rivits a smooth domed shape and painted where one cannot even see the welds. I am an amatuer home welder and do not have technical engineering training but the fan has worked well for the past 23 years as I assume a "single" unit due to the welding. Maybe someone with better technical know how will chime in to let us know whether the welding on my part is really ok to do or pure overkill!

What you did is neither "ok to do or pure overkill!" You now have a DANGEROUS fan.
Welding the four overlap joints of the two blades- two in front, two in the back, has made the fan far more prone to sudden blade loss than the riveted construction. You have now concentrated the flexing directly across your weld beads. The grain structure in the steel sheet metal the blades are made from is refined, compressed, and stretched directionally during the rolling process, essentially a type of forging. Your weld bead destroyed that. It annealed the metal and left a soft line with much less spring than the rest of the blade.

The fact that you now have 23 years accumulated stress from flexion on that fan makes it a real time bomb.

[Bill O'Brien]

Question: Which fan EACTLY does this discussion pertain to? I have an original 2 blade aluminum one piece fan on my 28 A. It seems that this discussion regards a stamped fan with rivets.. ??

Thanks gents...

[Blessyouboys]

Originally Posted by Bill O'Brien

Question: Which fan EACTLY does this discussion pertain to? I have an original 2 blade aluminum one piece fan on my 28 A. It seems that this discussion regards a stamped fan with rivets.. ??

Thanks gents...

The original fans were not aluminum, they were steel. They are prone to cracking near the hub, rusting internally and failing with often disastrous results.

[Don/WI]

I would be interested for $100.00 or close to that. Anything more I would take my chances with an aluminum 2-blade. Don/Wi

[hardtimes]

Originally Posted by MikeK

Yes Brent, perceived value. I have no issue no mater what the new fan costs- $1 or $1,000. I simply won't use it at any price point because it doesn't provide the one thing that would be a plus for me- increased reliability vs. a stock fan.

To me, in a fine point car an original fan is 100% reliable and I would see no benefit from any replacement fan. Why? Realistically, a car in fine-point is a low hour, slow speed car and will not see accumulated hours of fast highway touring. Has anybody ever had an excellent original fan break in fine point during judging or on the mandatory tour? Despite all the broken fan horror stories, there are still plenty of excellent originals, I have a few of both the early and late design. Sure, a pitted, cracked, welded, ground, bondo filled fan painted to look new is a bomb, but does anybody laying out the bucks for fine-point really do that? Then maybe the new fan fits their perception of value.

If you do intend to regularly tour with a car, then I see either an excellent original or the new steel fan as equally suspect in long term reliability, and both unacceptable to me. Same basic design and materials = same failure mode. For touring you need a different fan, IMHO.

Perceived value. To my eye, those lousy aluminum repops stick out like a sore thumb with their thick edges, and are not the answer either, at any price point. One can spot it a mile away. It REALLY gets me when I see one of those aluminum trying-to-fool-you fans, and then follow the fan belt around to an alternator! Whats the point? In my mind, you get more respect just running a plastic fan rather than trying to fool almost nobody with the aluminum propeller. If you replace the original fan for increased reliability, I just don't see a new steel propeller fan as any better for someone who will do a lot of driving.

Cyclic work hardening - C'mon Brent, you do know what that is. Flex a fender at the bead a gazillion times on bumpy roads and it cracks. Or flex a fan blade by varying the load on it every time engine speed changes. Eventually, Crack!

MikeK,
Once again ...thanks for sharing your knowledgable perspective to this thread! 'CYCLIC WORK HARDENING' ..just how hard is that to understand to help put a stop to the general use of this poorly designed fan! I'm with you on buying the titanium bladed fan, but not a redue of a failed design!

[5window]

Since some Model A's have been running since they were made and many, many were in operation during WWII when they were 15 years old, I would be very interested as to whether there were historically fan failures reported when the A was new, or whether this is a problem with an 80 year old part. And while we're at it, do Chevrolet,Dodge and other fans from that era have similar problems today?

I don't have a fine points car, but I'd be a big "fan" of the "one for show and one for go" crowd. I really like my current radiator and hood top.

[FL&WVMIKE]

If he is taking a poll to see how many people would be interested in buying one, he could put me down for one, if it is in the $100.00 range. If he had to price it in the $300.00 range, only the most fanatic of the fanatics would be buying it, in my opinion. At $100.00, I think that most drivers would invest in a NEW fan blade.
I had one break once, but luckily, no damage. It went downward. Then, since I was only about two miles from home, I tried to limp home, slowly, with one blade. I had a long hill to climb, and since I was driving slowly, I had to down shift into higher RPMs. The whole car shook and the water pump disentigrated. Next time, I will break off the other blade or remove the belt. Live and learn !
MIKE

[1928Pickuppain]

Mines origonal to the car i have never actualy taken a good look at my fan. From what im hearing is that the fan is comprised of two blades welded to the hub?
If it were once peace stamped steal of medum dencity rivited to the a central hub made to look origonal (i see no reason that it would ever fail) all welds are prone to failure from fatigue ( I take it the weld is were these blades are failing?) I would never put a cast fan blade in my car the process of casting creates an extreamly brittle meatal that is porus, unbalenced with tones of microscopic cracks and air holes. thats why air plane props are mechiend not cast.

[ursus]

A repop stamped steel two-blade fan was briefly available from some vendors back in the mid 80's. I know because I have one that I bought back then and paid the princely sum of $47 for it because it was such a good replica of the original. Maybe somebody knows about these?

I never got around to installing it, lost it during a move, and wasn't able to buy a replacement. The vendor told me that the person making the fans had ceased production and was otherwise unreachable. I found the fan in some moving boxes about 20 years later and still have it but have yet to install it because I'm happy with my aluminum fan and not into fine-point judging.

So, please note that the repop two-blade fan has been done already but I don't know why it had such a short production run. From what I now know about the original, the big question is whether or not anybody has found a way to mitigate the potential faults of Henry's original.

[A400 Guy]

I would buy an authentic fan reproduction in a heartbeat.

[JD Miller]

For waht it's worth, probably not much, the original two blade fan was prone to failure within just a few short years after production.

Our local Ford dealer carried two blade and four blade replacement fans back in the fifties. They probably had them even before then. I was just too young to realize it.

Coming from a family of mechanics, grandfather and father, I'm very familiar with the two bladed fans that failed during the late fifties and sixties. These were fans that had not set out in the weather rusting on some abandoned engine. These were fans on rather low mileage cars that had been maintained

The two blade fan was a faulty design. It's a wonder that they have survived all these years and are still being used. My grandfather did not trust the two bladed fan, no matter how good it looked and free from any cracks. Whenever he could convince a customer the fan was changed to a four bladed, riveted fan.

We had a case of a recently overhauled Model A engine on a combine. It was parked next to the shop and was being "run in" after the rebuild. The engine was running at a fast idle. All of a sudden there was a loud noise as one of the blades broke free and drove itself into the side of the building.

When we toured with our Model A's back in the late fifties just about everyone that had a two bladed fan carried and extra. It was not uncommon to have one or two fan blade failures each year. Worst one was on the Pennsy Turnpike on the way to Bedford, PA, from NW Ohio. A very nice, low mileage 29 station wagon tossed a blade going through one of the tunnels. It destroyed the radiator and one blade ended up sticking out the passenger side of the hood.

So, Model A fan blade failure is not something new. These failures go back to a period prior to WWII. The longer these baldes were run the more failures happened. Two blade originals are just great on a fine point car, but you are looking for trouble running one of these "time bombs" on a car used for daily driving and touring.

Good luck!

[Chris in WNC]

I would definitely spring for this new steel fan for our unrestored Coupe.

our Town Sedan is a 20-yr old but still very nice driver-quality restoration.
the aluminum fan is good enough for it.

[28RPU]

I am new to stock Model A's and this information is also new to me. I never would have thought that a fan blade that survived 80 years on a car was designed defective. Now that I have read all of the posts and see that this has been an ongoing problem for most of the Model A's lifespan I guess I need to preempt the problem and change the blade. I do not have a show car so 100 bucks is out of my price range on a new fan blade so I guess I will opt for just a standard replacement.So the aluminum replacements are ok for just a driver then?

[Terry, NJ]

As a former welder, I agree with Mike K. You have a bomb! I would get that thing off the engine tonight and have it magnafluxed tomorrow. Mike explained it better than I can, but there is such a thing as the HAZ. The Heat Affected Zone and it's always right next to the weld. This is where most welds fail. It weakenes the parent metal (In this case, the fanblade)
This is where failure would occur. On second thought, throw that fan away! One day a tiny crack will begin in the HAZ. Later, you'll rev the engine and centrifugal force will take over and Bang. it will be all over but the crying!
Terry

Originally Posted by Michael P.

To the fellows that asked about the 4 blade repro fans. When I restored my '31 Slant Windshield 4 Door Sedan (160-A) 23 years ago I was concerned about the reports of the 2 bladed originals comming apart so at the time opted to buy a 4 bladed repro. Being a bit paranoid I took the new 4 bladed fan and spot welded over the rivits and also ran a small smooth bead at every seam where the blades overlapped. I then ground the longer welds smooth, ground the welds at the rivits a smooth domed shape and painted where one cannot even see the welds. I am an amatuer home welder and do not have technical engineering training but the fan has worked well for the past 23 years as I assume a "single" unit due to the welding. Maybe someone with better technical know how will chime in to let us know whether the welding on my part is really ok to do or pure overkill!