Technical early flathead Ford V/8 generator 2 brush vs 3 brush

I am searching for info, then looking for an actual generator for my '32 Ford sedan with a 59AB engine. Looking at 1933-1938/9 with fan mounted to front generator pulley. School me on the difference in 3 brush vs 2 brush and what years had what. 3 brush runs a cutout? and 2 brush uses a regulator similar to '40-'53?

I seem to remember putting an early pulley with fan on a late generator is a no-no because of the smaller weaker front bearing. Correct?

Tell me what I need.

Thanks in advance for all the knowledge!

Dave

 

you got most of it covered. 3 brush have the movable 3rd brush to change the output. in those days you would set the charge higher if planning a long drive at night. leave it high with no lights on will eventually cook the battery dry. so, the two brush came out with a voltage regulator for those of us too lazy to change the 3rd brush on the cutout system. and, yes the fan mounted generators have double row bearings for the load. the 2 brush will also make a little more amps, not much, like 35 vs about 30 max on the 3 brush, which really is usually set at about 15 to keep from cooking the battery. the only ford 2 brush with the big bearing on front was the 38 deluxe, ?, or 39 deluxe i believe, and you wont find one of those! but, generally, the fan mounted pulleys are all a tapered hole, and the later 2 brush, non fan are a straight bore with a key way, 2 brush, regulated thru the 40's. the green book has several pages on generators, and i believe only bruce lancaster ever could read it! the 2 brush with fan pulley must have been made for industrial stuff or trucks, because they do show up at swap meets. i sent my 34 genny to ej whittney co and they make it an alternator. not cheap, but looks correct and they have a solid reputation. not an expert, but hope i helped.

 

Yes Rusty Valley, you helped for sure. I really would like a 2 brush so I need to know for fairly sure how to identify one, like on C/L or fleabay and what years they were. I believe '39 standards and pickups had them as well as all '38's. "39 DeLuxe was like '40-'48. Things like terminals, or wires or? In general Model A and T generators hate me and die but my '40 still has one as do 3 of my '51 Fords and my old DB's but everything else got alternators! Still trying to decide on my 331 hemi in the '33 Plymouth but Chrysler did come out with their alt. in 1960 in the Valiant so it would be period correct on it. But, the '32 is gonna stay 6 volt generator.
Anyone else have any info?

Thanks,
Dave

 

Is this the part number I would look for? 79-10139

Dave

 

not sure about the part number, i can look tomorrow. a 2 brush will have 2 posts sticking out the side for wire terminals, a 3 brush will only have wires out the hole near the cutout. late non fan mounts will have a keyed shaft with a snap ring and no nut on the end, and the ones with a smaller castle nut on the end should be tapered shaft and big bearings. do you have the fan and pulley?

 

I have 2 or 3 different length fans for mounting to the pulley but no I don't have a pulley. I see "they" make fan mount pulleys for the '40 and later gens but been warned about bearing issues doing that.

Dave

 

Great info and @rusty valley hows the 38-39 big bearing with fan look on the outside. I have a few buckets of fan generators 20 or so . Also can the big bearing gennie be changed to a fan mount?

 

My 39 Indian has a 3 brush and a cut out. 2 brush had a regulator..

 

this is a good topic, wish i had a concrete answer. i did some green book investigating today, here's what i found. first, Dave's # 79 10139 is the part# for the front plate. 79, being 1937, 10139 fords number for that part. looking up the front bearing, 10094, it shows 2 required for models 18 thru 68, years 32 thru 36. so, one would summarize that those are the only unit with bearings made for a fan, but, we know that is not true. also, all those years are 3 brush, and have a smaller case size, and a smaller shaft size at the pulley seat anyway. shaft is straight, not tapered as i said in previous post. (memory is worn out) . so, the 2 brush units with a fan according to the book only use one bearing, same part #, but that cant be true either because the shafts get bigger with the 2 brush, and the case size bigger also. note in my photo, on left is a later 54 thru about 64ish genny available in 6 and 12 volt. 2nd from left is a 2 brush fan mount type. they have the same larger shaft size, and the same larger case size and length. never done it but i have heard you can put the front plate and fan pulley on the later 12 v case for a conversion if you wish. the shaft sizes measure strange, .587, and .668, which lands on nothing in my chart, closest to 15, and 17 mm. ? so, there must be a different bearing # to go with the bigger shaft, and is it fan worthy? must be if ford used it. anyone else got some info?

 

Good info Rusty Valley! Still confused though, but that's not unusual!

Dave

 

I'm running a 60's Ford generator with a 37 fan and pulley on my 8BA, will be interesting to see if I have bearing problems. Only have about 70 miles on it right now, ran the same set up on a GM one wire alternator on my avatar with no problems years ago.

 

while i have no personnel experience with the bearing size of a delco unit, i think many of the stories we hear about fans flying thru the hood are from modern alternators, and not old ford stuff. again, my opinion, no facts to back me up. so is it the metallurgy of the shafts, or the bearings? take a guess, thats all we can do. back to the original question, what 2 brush can hold a fan. i think we need to know more about the bearing on the big shaft later generators. as i said before, same part # in the bible, but not true if the shaft is bigger. another identifying tip would be the nut size on the end of the 32-36 takes a 9 1/6" wrench, the later big shaft nut takes a 3/4" wrench if i remember, noticeably larger. mac vanpelt chimed in the last time this topic came up, perhaps he will see this

 

In 1956 I was a high school teenager with a 24-stud flathead 34. My battery wasn't getting charged so I went to ye oulde Battery and Ignition shop. (Remember them?) Geezer/owner had me take off generator and bring it in. After disassembling it he showed me that it had originally been a three brush but had been changed to a two brush. He explained the 3-brush/cutout problem and told me that it was once common to make this change and add a voltage regulator. That had been done to my car at some point in it's life. So, ... there may be some of these converted generators "out there" to confound us all.

 

Wow! Plot thickens!

Dave

 

I found this on fordgarage.com

http://www.fordgarage.com/pages/generatorchart.htm

Dave

 

Looks like the gens I need are 81A-10000-D & E or 82A-10000-D & E.
81A's have 4 3/8" pulleys and 82A's have 3 5/8" pulleys.

Dave

 

Looks like 91A-10000 is the same gen but has a non fan mount pulley. I am thinking that is '39 DeLuxe?

Dave

 

dave, you're still studying, thats good, lets figger this out. keep in mind the prefix, like 81A, or 91A tells the year, and the part number for an assembly, or entire unit i'll say, is the 10000. problem is ford did not put a nice red oval ID plate on the gennys in that era like delco or autolite and the others. so, any numbers found on a prewar ford generator are the part number for that part, and not the whole assembly. so, with that in mind, no seller on ebay or anywhere else is going to advertise the generator as being the 10000 unit we want. the only way to know its two brush is by the terminals. usually two posts on the side, but i see in the ford garage site they are showing one post on the side, and one post on the back. thats odd to me, but may be of some significance. now the other puzzle is the bearing size. as stated in my other post the early 3 brush show the same bearing number as the later two brush, but with different shaft sizes that can't be right. perhaps a phone call to mac vp, or ej whitney the alternator builders would would settle it. let us know what you find

 

http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=6923
http://www.oldengine.org/members/so...Zc-Ford-Shop-Notes-V8-Electrical-Eng-303a.pdf

Looking at these 2 would go for the D as the E has a lower output.

 

A few pictures of the different pullies as well and you can see the one pulley has the .656 or 21/32 diameter hole.

 

Just to add to the confusion, they used to sell aftermarket fan mount pulleys which fit on to the shaft of the '40 -'48 2-brush generators. Those aftermarket pulleys allowed the modification of readily available 2-brush generators to mount a fan. I have at least one of those pulleys that is not up to the usual Ford quality.

 

@rusty valley , did not even see the rear post! I assumed the second post was just out of site. Didn't some of the flathead gens have a ground stud on the rear plate?

Dave

 

some more reading here.. https://www.fordbarn.com/forum/showthread.php?t=1529&showall=1 no mention of front bearings though

 

some bearing talk https://www.fordbarn.com/forum/showthread.php?t=144418

 

"If the generator and regulator and electrical system are in good condition but it is impossible to keep the battery fully charged because of considerable low speed operation, a smaller pulley may be installed. This will drive the generator at a faster speed and keep the battery charged. This smaller pulley is Ford part number 8BA-10130-C and has an overall diameter of 2.76 in. However, the life of the driving belt will be reduced because of the sharper bend as the belt passes over the pulley."
Fix Your Ford 1932 to 1955
by Bill Toboldt
Editor, Motor Service Magazine
Member Society of Automotive Engineers
1955

 

I was moving some of my gold (junk) today near my 1940 Ford V/8 air compressor and since I was near, as I do now and then, I turned the crank mounted fan to keep the rings from sticking. But before that I noticed something. It has an early 3 brush generator with a fan mount pulley! Doesn't need it either as it has the crank fan. I will switch it out and use it 'til I find a '39 gen with fan mount.
BTW, this air compressor runs great. 4 cylinders gas and 4 cylinders air. It was a factory made conversion. Little short straight pipes pointed up sure make a racket! been a couple 3 years since I've run it.

Dave

 

a couple observations from me. that seems odd that it has no holes in the front plate for cooling. cooling is important, and quite often the death of the 3 brush units if they are set up on the high end of charge rate. and, it looks to be the large pulley diameter which will give you slow fan speed, and not much charge happening at low rpm's. may be ok if you do a lot of highway driving and not so much on secondary roads or cities. i forget if you mentioned, but what are you running for lights? any other needs for big power? also, note the holes in the photo of all the gennys on the back of my honda.

 

forgot to mention, cool f'n air compressor!!!

 

@rusty valley , you are right, I see no air holes! Car in question is a '32 Ford Fordor with a later flathead V/8. Either a 59A or an 8ba with 59A heads, etc. 7" sealed beams in BLC headlights, '39 tail lights, hyd brakes, '36 trans, '32 rear. No accessories. Will be a road car so the big pulley doesn't scare me, especially with the 4.11 gears!

I used to pull the air compressor behind my '40 Ford Std Tudor w/ 286" stroker flathead, taking it to cruise ins, etc. No trailer hitch on the '40 now since I put new stock bumpers on it.

Guess I never asked, do you want to sell the 2 brush gen?

Dave

 

Dave, much as i would like to help you out, there are a couple problems with selling you my generator. first, we have not solved the riddle. to recap, 32 36 two tapered bearings, 37 only, two ball bearings, 38-39 standard shows the same bearing as the later non fan units. i have lots of the later units with one bearing, but without taking them all apart we dont know why 38-39 is different...or are they? gennys are heavy, i hate to ship something not known be to correct, and the real problem is i have too many running flatheads laying around so i bought a 27 roadster body this summer to further complicate my life with more 1/2 done money sucking garage hogging projects. prolly will use this genny here, its the only one i have. should have listened to my mother. here's the body, mac vp could solve the riddle i'm sure