Aluminum One-Piece Fan. Issue...Maybe...

[Smurkey]

After reading the numerous posts about the potential failure of the original steel fan I was persuaded to order the one-piece aluminum; this one from Snyder's.

Question is:

Anyone else have close clearance between the new fan and the inlet pipe on the radiator?

I had to add shims to my radiator base to the point that the bolts barely catch the nuts to make clearance. This, after I moved the hose down the neck, out of the arc of the fan. Still I have only about a 1/4" of room between the fan and the pipe. Opinions: Will this be enough clearance?

The radiator is a old aftermarket replacement that has been re-cored. It has the round pipe rather than the original funnel type inlet. Oddly the "original" steel fan looks to be cut down on the ends to make it a bit shorter as the ends are squared off versus arced like the photos in the JS.

Thanks--
Steve

[BRENT in 10-uh-C]

Steve, it sounds like you have already diagnosed your problem. I seriously doubt the Snyders-manufactured fan is going to fit. If you don't mind me asking, why are you changing fans?

[Jordan]

Originally Posted by BRENT in 10-uh-C

Steve, it sounds like you have already diagnosed your problem. I seriously doubt the Snyders-manufactured fan is going to fit. If you don't mind me asking, why are you changing fans?

"After reading the numerous posts about the potential failure of the original steel fan I was persuaded to order the one-piece aluminum; this one from Snyder's."

[Jordan]

Smart move on his part. I don't understand why anyone would run an original.

[Smurkey]

Brent,

Actually, other than the posts here I saw nothing amiss with the steel one. However, once I took it off and really gave it the once-over, there is a small crack (1/4" or so) developing at the base of one of the blades.

I take it you think the 1/4" of clearance is too tight for the fan not to hit the neck? What might be a safe gap?

Thanks
Steve

[V4F]

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you could trim the fan & rebalance ,

[green30coupe]

Originally Posted by RHD

Don't understand what you are saying. The inlet pipe from the radiator is a mile away and comes nowhere near the fan blade.
Do you mean the outlet pipe?

The inlet pipe of the radiator is connected to the water outlet pipe from the cylinder head via a rubber hose. (at least on left hand drive cars)

[Smurkey]

Inlet=top pipe, nearest the cap.

A mile away would be nice but it's about 1/4". Anyone think that's too close, or should the movement be minimal?

[BRENT in 10-uh-C]

Originally Posted by Jordan

"After reading the numerous posts about the potential failure of the original steel fan I was persuaded to order the one-piece aluminum; this one from Snyder's."

Jordan, I did read that however something that you may not be aware of is the biggest downfall to the original two-blade fan is/was the reason for these cracks.

Several years ago it was determined by some 'gurus' that harmonics (vibrations) is what caused these fans to crack, and not internal rust as most people cite. It was determined that in their tests, if the fan blades were shortened by a small amount and then rebalanced, this moved the harmonic vibration to a much higher RPM where the A engine generally did not operate in that range. I was definitely not trying to be "smart" or "critical", but I politely asked the OP what his reason for changing the fan was as I was curious if this was due to a crack forming, -or because of aesthetic reason. Again, the keyword that Steve made was the fan had been shortened which triggered my line of questioning.

Thanks for your reply Steve. Since I know of half a dozen or so touring Model-A's using the shortened original fan blade with apparent success, it begs the question whether your fan's crack has been there awhile yet gone unnoticed, -or if it is a recently formed crack. If there is merit in the shortened blade theory, it is plausible this crack has been there for awhile without enlarging.

[1931 flamingo]

I'm thinking the problem may be with your re-worked radiator?
I also believe the alum fan is a bit SHORTER than the original.
How did the metal fan fit?? Have you compared the two?? Do you have the correct water outlet on the head? What year are we talking here?
Brent: 1ST time I've heard about this harmonic bit and shortening an orig blade?
Paul in CT

[gwhite]

Originally Posted by BRENT in 10-uh-C

Several years ago it was determined by some 'gurus' that harmonics (vibrations) is what caused these fans to crack, and not internal rust as most people cite. It was determined that in their tests, if the fan blades were shortened by a small amount and then rebalanced, this moved the harmonic vibration to a much higher RPM where the A engine generally did not operate in that range. I was definitely not trying to be "smart" or "critical", but I politely asked the OP what his reason for changing the fan was as I was curious if this was due to a crack forming, -or because of aesthetic reason. Again, the keyword that Steve made was the fan had been shortened which triggered my line of questioning.

Hey Brent, always enjoy reading your posts both here and on the MTFCA website...curious how much should be trimmed off the original fan to move the harmonic vibrations up out of the A rpm range.

[Smurkey]

Brent

The crack could be decades old for all I know. Too fine to tell if it's older or recent.

That's interesting about the shortening of an original. I had no idea why it may have been trimmed. Heck I thought it might've been due to close clearances, but hadn't even noticed it was cut down til I took it off and compared it.

If this aluminum one taps the inlet I'm going back to the original and just keeping close tabs on it.

Steve

[jkcrosson]

I struggle to gain clearance on my 29 tudor. I did just recently find out that my car has a 30 31 front crossmember and according to the service bulletins requires an extra spacer underneath the radiator on 29 cars. I have always used a spacer but I thought it was a farmers fix not something specified in the service bulletins.

[BILL WILLIAMSON]

Originally Posted by 1931 flamingo

I'm thinking the problem may be with your re-worked radiator?
I also believe the alum fan is a bit SHORTER than the original.
How did the metal fan fit?? Have you compared the two?? Do you have the correct water outlet on the head? What year are we talking here?
Brent: 1ST time I've heard about this harmonic bit and shortening an orig blade?
Paul in CT

Yo, Paul, Dog here, Iffin' you cut 8" off each end of a stock "Guillotine" fan, then it would be safe & probly wouldn't viiiiibrate! Buster T.

[Tom Wesenberg]

Here is my original everything showing the clearance.
Almost original everything, the fan belt and hose are newer.

With your 1/4" clearance, I'd say the radiator inlet is off.

[springerpete]

I have a 1937 diamond engine in my '29 roadster along with a new Brassworks '29 style radiator. I too just replaced my old, rusted & failing 4 blade fan with a TAMS aluminum 2 blade. Clearance is not a problem with the outlet hose & fan as these later engines had longer outlet necks. But, I wonder if the clearance issue talked about here is due to a short neck combined with an older style radiator ?

[Tom Wesenberg]

The year of the motor doesn't matter with the outlet height.
All 1928-9 style radiators should have the short neck.
All 1930-1 style radiators should have the tall outlet, as these radiators are taller.

[Tom Wesenberg]

Here's a picture showing the two different water outlets. If I use my small pocket tape and measure tight along the back side I get 6" on the tall outlet, and 5 1/2" on the short one.

[Logan]

Either your radiator inlet is off, or you have the wrong neck on the top of your head

[jkcrosson]

Originally Posted by Logan

Either your radiator inlet is off, or you have the wrong neck on the top of your head

Does anyone know of a drawing of the correct radiator inlet shape. I have fought this issue with what I thought was an original radiator. Maybe it's a very old replacement.

[Tom Wesenberg]

Originally Posted by jkcrosson

Does anyone know of a drawing of the correct radiator inlet shape. I have fought this issue with what I thought was an original radiator. Maybe it's a very old replacement.

Will a picture of my 1928 work?

[jkcrosson]

Yes it will work enough for me to know mine is nothing like it. I have the radiator out so I'll take a picture when I go home for lunch.

[dave in australia]

Wouldn't a sagged chassis also cause the fan to be closer to the pipe. If the rear of the engine drops, the upper forward will move back slightly from the rotation of the engine along its length. Just something else to think about.

[Smurkey]

Well I attached some pics.

The first three are the original steel fan. The baby's cut down to 13 1/4"...didn't even realize it. The one of the hub shows the crack forming. The last one shows the clearance between the inlet neck of the radiator and the fan AFTER shimming. That's about the best I'm going to get.

Thanks for all the interest in the subject and the tips...I'll let you know after I refill the radiator. Waiting on a lower steel pipe for the engine inlet...Mine looked like Swiss cheese; the paint was literally holding the coolant in.

Steve

[Farrell In Vancouver]

Hey Smurkey! Any chance your engine is too high? Will the hand crank fit in the crank nut?

[JBohannon]

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If anyone has any doubt that the original fans can and will fail I can tell you that I am living proof that they can. The truth is I really think I am alive today because of reading the post on this forum. A little over a year ago I was standing on the carb side of the engine revving it up a little and one of my blades let go. It came so close to my head I felt the air and heard the noise but it went so fast I did not see it. I had the carb side of the engine cowl open and to my knowledge it never touched a thing as it came out. I live in the country and I can tell you after searching for it for over a year I have still not found it. I have no idea how far it flew. I must tell you that mine did have the very small cracks near the base but I just did not pay much attention. But in this forum I had read do not put yourself in the line of fire of the blades and really think that saved my life. I kept my body and head near the back of the engine but I think it missed me by maybe inches.

[larrys40]

Steve,
Good advice above from Tom on the Water necks..... sounds like the radiator neck may be on of the issues. Take a line of sight from the side with the hose off, making sure you have the correct height ( not sure if it's 28/9 or 30/31 you are working with ( despite 29 photo in avatar) but I would lean toward fixing the radiator and core problem....
I would not put a cracked fan back on no matter how long you might feel it's been there. Should be heliarc welded properly if repaired for re-install.

Good luck!
Larry Shepard

[Smurkey]

Hey, just a follow up. The gap was/is sufficient. Just went for a 20 mile cruise (first on of the season) and all worked well. Now with some peace of mind about the fan.

Happy with the thermostat I installed too!

Steve

PS the stainless lower coolant pipe from Brattons is a beaut. Thick gauge, looks right, almost a shame to paint it black. Well worth the extra 3-4 bucks!!

[machine girl]

use the 6 blade plastic, want to show your car put on an org, 2 blade alum is still a fake

[BRENT in 10-uh-C]

Originally Posted by machine girl

use the 6 blade plastic, want to show your car put on an org, 2 blade alum is still a fake

Tests have confirmed that a 6 blade fan is actually less beneficial than an original style at speeds greater than 20 mph. The reason is the 6 blade fan creates a curtain wall of air which does not allow additional air to flow across the fins. A 2 blade fan will keep all but a fully loaded AA truck cool at speeds under 20 mph. Over that, you don't even need a fan to cool the engine.

[ericr]

out of curiosity, does anyone know if the '32 etc. Ford fans were of the same design?