MTFCA Forum

I saw that the plastic fan offered for the model A will fit on a T. Is this true?
Is it a good thing to do, to prevent a cracked T fan from exploding and trashing the radiator? I've got a new brassworks I'd like protect.

Here is a version I have done. The fan is 13” diameter so will just fit behind a brass radiator

Here's the link I found.

http://www.spokanemodeltclub.com/model- ... pgrade.php

This prevents broken fan blades too https://www.modeltford.com/item/3961C.aspx

Most of the failures occur with the four riveted blade fans on the earlier T's. These need to be monitored. The one on my 1912 van began making clicking noises. I caught it before the blade liberated itself.The later two types are far less prone to failure in my experience.

Allan from down under.

The cracked four-blade riveted fan on my '27 was just about the first thing that I replaced.

When I put the fan on the car 2 yrs ago, I looked at it closely and found nothing of concern. I just don't want to spend $1000 on a new radiator if it fails.
Thank you for your thoughts.

Are the four fan hub mounting holes located in the same place on the T and the A?
T and A fans interchangeable?
I'm wanting to find a bolt on plastic upgrade.

Professor Fate wrote: ↑

Sat Jul 08, 2023 9:51 am

Are the four fan hub mounting holes located in the same place on the T and the A?
T and A fans interchangeable?
I'm wanting to find a bolt on plastic upgrade.A-8600-P.jpgIMG_1u7tgdh399.JPG.opt558x836o0,0s558x836.jpeg

From your post of the Spokane club site, that plastic fan has oval holes for mounting, so yes, should fit the fan pulley, except, the modern hub for T with the sealed bearings would be the best to use with that multi blade plastic.

Thanks Dan.
I'm going to do the hub upgrade with the fan.

Jerry VanOoteghem wrote: ↑

Sun Jul 02, 2023 8:38 am

This prevents broken fan blades too https://www.modeltford.com/item/3961C.aspx

Yup. I bought one. During my post-purchase inspection I found that the original had a cracked blade. I bought that and a sealed bearing pully from Lang's. BTW: If I knew the engine had a cracked fan blade, I would do one of two things immediately; Not start the engine, or remove the belt. You would not believe the amount of damage a broken fan blade can do.

Back in the 1970's Ford had a bunch of flex fans that would crack @ the flex point. The cracks pressented them selves as a clicking noise under acceleration. Several mechanics where hurt & one killed by the blades flying off. Radiators are cheap compared to a trip to the E R.
Craig.

I was in a 1970 IHC Scout 6 cylinder that threw a fan blade. The blade almost went through the hood, and the unbalenced remnant of the fan ripped the bearing extension off the cast iron water pump. If anyone had been leaning over the engine, they would have been gutted. NEVER run a bent, cracked, or loose fan. I've seen scores of cracked flex fans. An unbalanced fan can cause the water pump/fan shaft shaft to break. Dry bearings can do the same.

A number of vehicles in the 60's-70's had a water pump pulley that required a specially formed washer-like reinforcement between the pully and the hub. These washers were sometimes left out, and the result was often as not a cracked fan pulley.

Using the wrong hardware on fan mountings can be dangerous.

This thread was a prophetic for me. Just took the Speedster for a test run. After turning around, as I was pulling away, I heard something that sounded like broken metal. I looked back quickly and saw what I thought was a fan blade flopping to a stop on the side of the road. Sure enough, I got back in the garage and opened the hood...

Lost one blade. No damage, thankfully. That could've easy destroyed my newly recored radiator. I'll be getting the new hub and plastic fan.

I run a Model A plastic fan in my coupe. Bolts right up to the T hub. Cools nicely with very little tension.

Plastic fan installed. 1rst run with it pending this a.m. I was unable to center the fan perfectly on the pulley, because there's no centering pin or any way provided to do it. I had to devise my own method, which I think is very close but not exact.
Has anyone else done this conversion and been successful?

Dan,

I found that the new ball bearing hub that I ordered wouldn't work with the old shaft I had, so I used the old hub. Had to grind down the rivets on the front face of the hub and drill two additional mounting holes for the bolts, but I was able to get the new fan mounted on-center and the whole assembly back in using the old hub and shaft. Not much clearance between the radiator and the fan blades, but there's enough and it works without any interference.

A fan that moves more air will use more power, and may need for the belt to be run tighter than normal to be fully effective at higher engine speeds, especially at low car speeds.

An ideal fan would move more air than the stock fan at idle and low speeds, and de-clutch at higher speeds. An older model Japanese thermostatic fan might do that.

A metal flex fan might not function as designed at higher speeds, since Model T engines don't typically reach the speeds that modern 4 cylinder engines do.

Some modern replacement fans will do a good job of moving air, but make a lot of noise doing it.


Old, low speed Fairbanks Morse stationary engines used a 4 blade fan similar to that used on Model Ts.
An oil operator replaced the stock fan on a FB engine with a modern "improved" fan. You could hear that fan moaning a mile away, night and day.

Unable to set plastic fan dead center on pulley because of lack of a key or pin.
I'm afraid of it walking, so I put the original metal fan on the ball bearing hub for now. Gonna run it as is.
So much for succeeding for now.

Dan, now you are talking of a true upgrade, from an ugly plastic monstrosity to a genuine model T part. Well done.

Allan from down under.

I gave the original fan a really good look over before I put it back on. Hope it lasts....

I've read here on the forum that some have eliminated the fan altogether. I live rural and never get stuck in traffic, and live on the bottom of a glacial lake. Terrain here is flat as long as I run the Connecticut river valley north-south. Hill climbing is very rare.

So maybe no fan will work fine as long as I'm moving 20mph or more? Thoughts???

I've run my car with no fan in very hot temperatures with no problem, but you MUST keep moving, and avoid tailwinds. Think in terms of airspeed.

If you try this, remove the fan, since it will do no good without a belt, and may restrict airflow.

I'm pretty sure my car ran and completed the Montana 500 with no fan installed.

Hi Dan and Pat,

Regarding running the Model T "sans fan":
The Metz Model 22 has a thermosyphon cooling system WITHOUT a fan. The engine hood has no louvers. Beneath the engine there is a sheet metal undercover attached to the bottom of the frame and encloses the space from the bottom of the radiator to just in front of the exposed flywheel. The spokes of that flywheel are shaped liked fan blades and draw air through the original FLAT TUBE radiator and cool the engine reasonably well. The cooling system is well thought out. My '14 Metz doesn't boil unless idling and stationary for a long time.

And Dan, I concur that motoring on both sides of the Connecticut River does provide rather flat terrain, but here in The Shire (CheSHIRE county of New HampSHIRE) we do have hills and lots of them. I doubt that I'll be removing the fan from any of my Model Ts.

As is often stated on the Forum; "Your mileage may vary." Bill.

Sans fan may be the inevitable way of my future....

Why are you running a fan at all ? With a good radiator, there is no need.
fix the problem right and don't waste your energy chasing symptoms !

Problem solved, problem STAYS solved !

This thread has gone from modern, high efficiency fans to, you don't need no fan at all. What's the goal here? Why this hatred of fans? Is there some satisfaction in pointing at certain component and claiming, "you don't need that!"

Buy a new fan blade, or a good original one. Inspect at least once a season and you'll be just fine. And, for heaven's sakes, when a guy is working on his T, with the hood up, revving the hell out of his engine, don't be one of the Curious Georges who stand over the car, lined up perfectly with fan, waiting for it to turn into shrapnel. He may not have ever checked the condition of his fan blade... but you should check yours .

Ran the '26 to check to see if all was ok... wow, the belt even stayed on! Whaddayaknow!
I'm done with this "Fan"- tastic escapade for now. Planning on inspecting the fan a few times a season.
Every little journey teaches me sonething.... this one I learned a boat load...

I have a 1914 Touring with the proper fan blade for that year. My engine runs cool as long as I am moving, but the early blades have very little pitch so it gets HOT when you are sitting and idling. If there is a long line at a drive through I shut the car down and go inside because it will overheat if I sit and idle for a long time....
I have been thinking about putting a higher pitched blade on from a later model T or one of those plastic fan blades with lots of blades. I have one of those plastic fans on my Model A and it works great.

bdtutton wrote: ↑

Thu Aug 17, 2023 4:50 pm

... I have one of those plastic fans on my Model A and it works great.

Does the model A fan pulley hub have an idex or pin to center the plastic fan?
That is my sole issue right now.

I don't know if its worth it Dan. With over 15 million model T's made and thousands still being driven after 100 years, I just haven't seen the need to replace the original Ford fan. In my 50 plus years in model T's, and although none of these things have happened to me, I think statistically, it is more likely you will break a wood spoke wheel, break an axle shaft, shred a mag ring, break a crankshaft, over-center your steering arm, or get hit by a distracted driver.

Any fan that has been bent and straightened is suspect. Any fan with a crack or loose rivits is suspect. Any fan that is heavily rusted is suspect. A fan that shows uneven pitch or wobble is suspect.

Fans on lower speed applications usually show visible evidence of problems well before they fly apart.

Fans, steering and suspension parts, brake rods and internal brake mechanisms, and wheel and tire assemblies need to be looked over from time to time, as do brake lever ratchet parts. Rear axle hubs and nuts need to be kept tight. Frames and frame crossmembers need to be inspected once in a while, along with motor mounts.

Bolts and other fasteners need checked and tightened as necessary.

New, late style fans are a bargain @ $10. Cheap insurance VS a $1000 radiator.

Put a new 4 blade fan on a ball bearing hub and be done with it. The car won't overheat under any ordinary conditions if it has a stock type fan and a good radiator with 50/50 green antifreeze, the belt tight enough, and the spark managed properly.

If you have an older car with the arm and spring type fan pulley mounting, make sure that the mount assembly is not excessively worn and that the spring is in good shape with good tension and no excess wear at the end hooks. The fan should run true with no wobble or shake.

Professor Fate wrote: ↑

Thu Aug 17, 2023 5:56 pm

bdtutton wrote: ↑

Thu Aug 17, 2023 4:50 pm

... I have one of those plastic fans on my Model A and it works great.

Does the model A fan pulley hub have an idex or pin to center the plastic fan?
That is my sole issue right now.

Professor Fate - It has been so many years since I have had the fan off of my Model A that I do not remember. If you get it working on your Model T, let me know how it goes because I have been asked to be in several parades and I am going to keep saying NO until I am sure my car has enough airflow to keep cool. Ford must have known there was a heating problem on the early Ts because the fan on the later cars has more pitch. I like the plastic fan because it moves a lot of air at low speed and is not prone to failure.

The model A fan coupled with the roller bearing fan pulley hub would be a really sweet set up.... but there is currently no way to index and pin the fan dead center on the hub. I'm hoping somebody smarter than me figures it out, because I'd love to run this set up on my cars.
Running the roller bearing hub with a good metal 4 blade for now....

Good point Dan,
Looking @ Les's fan he has a stem to locate the fan centered on the hub. What doe's the ball bearing hub look like on the front? Can a piece be machined to center the fan & incerted into the hub?
Craig.

Craig Leach wrote: ↑

Fri Aug 25, 2023 9:53 pm

.... Can a piece be machined to center the fan & incerted into the hub?
Craig.

One could certainly machine a piece to fit into the face of the pulley hub that must have a protrusion thru the center of the existing plastic fan hub.
But the other issue is that the fan hub screw holes, all four of them, are ovals not circles, and do not touch the mounting screws. The only support there comes from the screw head, lockwasher, and flat washer.
Too much play for my liking.

Note the oval shaped holes in the plastic fan hub.... and the recessed area on the face of roller bearing pulley near and around the bearing. That's what I discussed in the prior post.

I would not be comfortable with the mismatched fan and hub. I see no virtue in the plastic fan. It might move more air at very low speeds, or not, but I doubt if it would offer any improvement at higher speeds, since each blade would be running in the wake of the preceding blade. The large diameter hub of the fan would block air at any speed.

A good repro steel 4 blade fan on a ball bearing hub will do a good job, and it will move about as much air as the T belt drive will allow. It may offer other benefits, such as a small damping effect on torsional crankshaft vibration, and it will certainly look more like something Ford would have put on a Model T.

I'd inspect a new repro steel fan, looking for any irregularities, and check it for good balance, consistent blade pitch, and blade alignment. Hub bolts on any fan ought to be tightened evenly, using proper washers and lock washers.

This whole plastic fan journey I've been on for the last month has been at the least, very interesting....

After reading countless valuable input on this forum, and discussions with the knowledgeable T afflicted bretheren, the appeal of plastic is waning quickly.

I'm feeling like new repro is the way to go, but I haven't given up totally on plastic just yet....

Humblej wrote: ↑

Fri Aug 18, 2023 7:58 am

I don't know if its worth it Dan. With over 15 million model T's made and thousands still being driven after 100 years, I just haven't seen the need to replace the original Ford fan. In my 50 plus years in model T's, and although none of these things have happened to me, I think statistically, it is more likely you will break a wood spoke wheel, break an axle shaft, shred a mag ring, break a crankshaft, over-center your steering arm, or get hit by a distracted driver.

Ya. Ford used terrible quality fans. Mine only lasted 90 years before it cracked. My '27 now has a Lang's reproduction that to my eye is identical to the original.