I’ve been doing a lot of research and haven’t been able to nail down an answer as to what Ford flathead fan is the thinnest. Here’s the story: I am building a ‘32 roadster. Stock dimensions, model A front cross member, stock style re-pop firewall and an 8ba flathead mated to a T5. I am in mock-up stage now and setting the engine in to determine the motor mount position. Radiator and grille shell are mounted, firewall is mounted, and I am setting up the Powermaster alternator (gen look-a-like) in the stock position with the fan ***embly mounted below the alternator off a 2nd belt. I’ve got a 18.5” wide fan off a 1950 F100 (I think) that I plan on t******* down to 15.5” wide. With this setup, it appears I am going to need to do some significant firewall t*******. My tentative motor mount location to give me ~3/4” clearance from the radiator to the fan is about 8.5” back from the center of the radiator mount holes. This is causing the engine to hit the firewall. Any help to get the engine moved forward would be nice without going to the lengths of moving the front cross member, or switching the water pumps to 59a style (and thus using a different distributor and cover), or mounting the fan off the alternator and going with single belt (I’ve read the powermaster bearings cannot handle the load of a fan, plus I believe it would put the fan too high and I would run into hose interference), or switching to a flat firewall. I definitely do not want to go with an electric fan, either. Only options I see left are to run fanless, or find a fan that is thinner. I would still have to make firewall trims, but if I can gain 1/2”, it would help. So the question is, what fan is out there that has blades in-line with the front face of the center of the fan and do not stick out towards the radiator? There is a good possibility that I just run what I have and do the firewall adjustments as needed, but if there is another fan option that could save me some firewall fab hours, I’d be interested. What do you all think?
If you dress up your 8ba to be like a 59a block and distributor you gain 1 1/2" right off the bat. Plus, dont have to have that girlie lookin dizzy up top for god and everyone else to see
Moving a distributor to a front mounted is no easy task. The cam will have to be changed. I’d use an electric fan vs no fan.
Building a car from scratch is not an easy task either. but, making things fit is part of the deal. an inch ana half is a lot of space in an old ford. I cut the gear off and slotted a merc cam for my 59ab, not a big deal really, and then you can use all ford fan stuff
Here’s what I did to pick up some space: took an old fan ***embly apart, saved the shaft and mount. Took a mid ‘30s generator pulley and machined it out to accept a bearing. Machined off the front half from the crankcase pulley. Used an offset Generator bracket to tip the generator off to the p***enger side and effectively run on one belt with an old Ford fan. If I had to do it again, I would have offset the generator to the driver side so everyone could see the distributor better. As it sits, the center of my motor mount holes is 5 inches back from the radiator. I did cheat a bit by moving the radiator a tad bit forward but left the crossmember where it was. Did all of this before I knew of the HAMB which probably would have helped me figure another way.
If I had done my research regarding making an 8ba shorter via the 59a tricks, I would have gone this route. However, I’m a tad too far invested in 8ba parts at this point to turn back. Gotta make a business decision and move forward with the 8ba parts and deal with the length.
AVater - that is a slick setup and quite resourceful. I’ve been thinking in the back of my head if I could make a single belt work while keeping the fan low in the radiator. Right now I have the Bob Drake fan hub (https://bobdrake.com/products/1942-...MI-cuPvOnW9AIVdgOzAB033gSREAAYASAAEgLsGfD_BwE) and I will have to do some looking and thinking to see if I could adapt this ***embly to run a single belt with the offset bracket. I’d have to factor in labor cost at a machinist too since I do not have a lathe (although I’m seeing more and more how a small lathe would really help). Thanks for the reply and picture.
just caught an episode of ian roussel's show, which covered a c-cab model T build. he used an aftermarket "flex-a-lite"-type fan to solve a similar problem. i think the fan he used was aluminum, though.
That Ian is an inspiration. Guy just jumps in and starts cutting and welding. Turns out some masterful work in short order without a ton a high dollar equipment. I’ll look into the flex-a-lite option to see if it’s any thinner. I finished cutting down my current fan to 15.5” last night and slapped it on the block. I’m starting to think I’ll be making firewall accommodations soon for this setup. My goal is to make the firewall reliefs look factory-ish. Only cutting where it’s needed and not just taking a rectangle chunk out to be replaced with a recessed rectangle chunk. Could be tricky.
Thanks for picking up on that! Looking at the pic made me realize the fan appears a bit low. I was going by the Van Pelt diagram and some other pics I’ve seen here and elsewhere. The gen/alternator mount is as low as it can go if I recall, so moving that up to mimic a nice tight belt should bring the fan up a bit.
Trouble with those flex fans is that the ones that are flat in front often are the ones like the one on the right that don't pull enough air to write home about as they are a ricky racer item designed for low restriction rather than actually pulling a lot of air like the one on the left. The one on the right was on my 48 for a long time and barely pulled any air at low speeds..
That’s the real world info I need to help make a decision. Thank you. I hadn’t thought of the actual airflow function of the fan….just how to gain a dang 1/2”.
AVater: I respectfully suggest that you replace that stock metal fan as it is so badly pitted making it subject to hairline cracks and fan blades breaking. Many years ago, I had a fan that looked like yours literally fly apart. Blade pieces went thru the hood and into the radiator. Over the years, the metal had work hardened and cracked due to flexing and then BOOM? No warning.
I'm running an 8BA with a 12 volt generator and a 37 generator fan and pulley machined for the later generator, the front pulley is machined off the crank pulley and I'm running truck water pumps. The fan is about 1 1/2" from the radiator and runs cool. I originally mocked it up with an alternator and 37 pulley but went with the generator since it's a traditional car.
I used an offset generator mount and modified my fan mount to bolt to the front of the manifold. This would get your fan back that 1/2” you need. This aligns all the pulleys for a one belt setup.
I like that set-up. Simple and saves some room. But I am going to run the power master alternator (gen look-a-like), and they specifically state a fan cannot be run off of it. The bearings aren’t designed for the load of a fan.
Thanks, Aaron D. I went through your build thread earlier (incredible, by the way) and made note of your set up after you suggested my fan mount needed a 180 flip to get the fan up higher. I tried the 180 flip last night after watching the Army/Navy game and the fan flip won’t work for me because it will hit the alternator housing unless both the fan and gen mounts are at their extreme adjustment spots (gen mount nearly as high as it will go and fan mount nearly as low as it will go). I envision having belt mounting and adjustment issues with the fan mount flipped. It has to be the way I have it in the pic. With the gen mount moved up to a more real-world position, the fan is about 1” below the center of the radiator. Not ideal, but I think it will cool fine…especially if I add a shroud. I’ll have to do some thinking and decision making to see if I should move directions and go with the offset gen with the fan mounted off the intake and a one-belt system like you have. I believe I will still need firewall mods if I go this route. But an added benefit would be to get the fan up higher to the desired top half of the radiator since I would be able to flip the fan mount. Decisions decisions
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