I'm putting an 51' 8BA in a 31 roadster, Thickstun PM-7, with the generator up top & center. Switching from the double narrow belt water pumps, to the wide belt truck pumps to clear the side mount distributor. Double sheave truck crank pulley (cutting outer sheave off). Trying to figure the wide belt generator pulley out. I'm looking to use the generator mounted fan. I've got a 39' pickup generator with the fan mount pulley, not a threaded pulley, but keyed, and has the same bore as the F-1 generator that came with the engine. In order to swap this pulley to the later generator, it would require a spacer between the pulley and the front bearing surface, or the cooling fins would bottom out. I would also have to mill the inner front to make room for the retaining nut, not sure how much meat that will leave. I'm also looking to convert to 12 volt. Is there a later 12 volt generator that would be a better swap, rather than converting? Is there a double pulley generator armature that would be longer, not requiring me to mill the inner part of the pulley? Or is converting the 39" to 12 volt, and removing the generator mounting portion from the front end plate so it would fit the 8BA mount an option? In regards to the cooling fan, am I correct that the 37-38 & 39 standard are the shortest? If my information is correct, this is Ford's part #78-8600. It appears that this is also shown as a part number for Ford 8N & 9N tractors, and mount to the tractor's water pump. In looking on that auction site, an 8N fan has a 8600 part number' and it appears that the blades have the correct curvature, and the blade tips are slightly different in shape, but I can't say what diameter they are, or if the bolt hole spacing is correct. They are priced reasonably new, and dirt cheap used. Any 8N / flathead guys out there that can confirm if they are the same? Any help is appreciated!
Im betting the generator you have is an earlier unit, the 39 generators that i have have a screw on pully with a clip on the end. 38 and down may have the keyed pulled but then ive seen a few 39s that had a key too but im betting they were replacements from back in the day. Is it a 2 brush generator or a 3 brush? 39 to-48 generators should all be a 2 brush and all the same with the exception of the pully. Why dont you just have your 39 generator converted to 12 volts and use it? I know you can take a 55 ish ford generator (what ever was the first year for ford to have 12 volts) and bolt that into a 8ba generator mount but you still dont have the fan hub on it. jeff
A long time ago there was a pulley made that allowed the 39 fan to be used with a 40 generator. All the old generator shops sold them. It let us use the generators that had a voltage regulator rather than a cut out. Mine was a crappy pot metal thing that striped and let the fan get into the radiator just enough to make a noise. When I pulled over and shut off the engine the belt would tighten it back up. It took me a while to figure out what was going on.
The 39' generator I have is off off a 39" pickup, pulled it myself. It's a 2 brush, and came with an adjustable regulator attached. The issue with using the 39' would be mounting it on an 8BA style mount and having the pulleys line up with the truck pump pulleys. Will the 56-63? 12 volt field coils & armature swap to the 39' case? If so, is it possible to cut the mounting legs off the front end cap, and drill an indexing hole to mount in the 8BA style mount?
A, you may be taking 8600 as a part number when you say "same"...8600 is just the root of the number. Every Ford fan made since 1927 would have 8600 in there...the complete number, like 78-8600, describes the fan for its original application...so 89-8600 and 78-8600 are most likely entirely different beasts.
To use a fan on a '40 generator, and convert to 12 volts, I bored-and-keywayed an early ('38ish) pulley to fit over the later '50's-60's armature, and then cut the front side of the pulley for room for the '50's nut. Also made a short spacer for behind the pulley, just like you described. I didn't think the pulley had enough meat to cut the frontside too far, so I didn't counterbore deep enough for the washer. I just use strong Locktite. All this is on the '40 case and front gen mount, mounted to a '39 Merc block, early Weiand intake, in a '32 Ford. The early intake was not long enough to place the generator pulley inline with the pumps and crank, so I also machined a 1/4" or so spacer to move the generator forward. You need to keep watch that the armature nut stays tight, and watch those bolts holding the fan to the pulley too.
Bruce, just thought I'd share this about part numbers. You (of course) are right and the numbers are still done the same way. I work for Ford, in prototype. We divide the part numbers up as: prefix-base-suffix Prefix tells the program or car line Base tells the type of part Suffix tells part level or version AA being the first incarnation, then AB and so on. Example, fuel tanks all carry a 9K007 base number. Wheels are all 1007 base. I know you find these things interesting, sorry to hijack.
If we are talking early Fords (1928-1948) just a couple of minor corrections. The original part number carried no suffix, the first revision of the part was A, the second B, etc. The base number for the fuel tank is 9002 and the base number for the wheel is 1015. Charlie Stephens
Thanks for the input, guys! I guess I was headed in the direction alchemy did, just using the 51' 6 volt generator and anticipating converting it to 12 volt. I haven't taken any accurate measurements to know how much I would have to machine from the inner portion of the pulley to get the nut to thread on, but it looks real tight, as alchemy stated above. That's why I wondered if it would be easier to use the later 12 volt generator or the 39' generator I have, and convert it, although it has the early style mount and I'm trying to put it in an 8BA mount to line up with the truck pumps. As far as the tractor fan, I found this reference (see link below) showing a 78-8600 as an optional winter fan (puller type) for ford & ferguson tractors. That's why I presume that perhaps, a fan for any 2N, 8N, 9N would have the same bolt spacing, perhaps other length options, and just don't know about diameter. I'm looking for someone with a 8N to see if I can get some measurements. Any further input is appreciated. http://www.yesterdaystractors.com/cgi-bin/viewit.cgi?bd=nboard&th=70561
I just meant that the same numbering systems are still used today. The numbers I used as an example are current day. Just interesting that things don't change much sometimes.
Got so wrapped up in trying to figure this Generator/pulley/fan deal out, I forgot there is a antique engine (hit & miss), antique tractor and car show a block from my house this weekend. Ever get so consumed, you can't see the woods for the trees? Hope to find some early Ford tractors there so I can check out the fans.
Stopped by an older tractor dealership today, an found several older Ford tractors, including an 8N. Of the four I measured, all were the same. It appears, as best I could measure, 15 3/4" overall diameter, 2 1/8" - 2 1/4" from hub mounting hole to mounting hole (I couldn't measure diagonally, since the fan was installed), so I think the bolt pattern is correct, and 3" from face of fan @ rivets, to the rear of hub where it bolts to the pulley, this would be about the same length as a 37' fan, if the info I found on the "Ford Barn" is correct. Can anyone confirm the length for a 37' fan? The tractor fan has a more squared off end to the blades, than the petal shaped ends that I've seen, and may be a good alternative, if you needed to shorten one, rather than hack up a nice stock fan.
Picked up an early Ford tractor fan, six blade, from a junk yard. I can confirm that this bolts to the Ford generator pulley. Overall depth from face of fan (point closest to the radiator) to the hub mounting surface is 3 1/2". It appears that the four blade tractor fans are the same depth. Can anyone confirm the depths of the Ford fans from 32-39? Tried searching to no real avail. Thanks.
The Jalopy Journal
