The B.B. in the title represents that this is from the archive of the late Bill Bently, who ran a flathead informational site before he passed away. All threads from this source will be titled using the B.B. identifier on this site. We’re archiving some of the threads, so that his work is not lost or forgotten and so they will continue to educate flathead enthusiasts for years to come.
mr bill (Jan 5 2000 2:11PM) 6V generator to 12V
Has anybody changed their generator to 12V? I took mine to a repair shop to be converted and I was told that the existing field coils are too short to convert unless I went with a longer case. Since a longer case will not fit with my dual carb setup I am wondering what to do. I don’t want to use an offset mount as this will require changing the fan set up. I am thinking that maybe I should keep the 6V. Any ideas?
Converting gen. V EK: Converting a 6V generator is pretty simple since only the fields HAVE to be changed. Use the 12V generator fields from early V8 Falcon-Comet-Mustang generators… they bolt up in the 6V generator case. (If you’re running a ’39 or ’40 generator, you’ll have to drill a hole for the ground since these generators are only two post units and the fields are wired for 3 posts.) Someone said the cases themselves are interchangeable if you drill a hole in the case for the locating pin. I don’t know if that’s true or not since I’ve never done one that way. (I usually am working on a chrome generator and want to retain the chrome case.) The armatures for the 6V flathead and the 12V generators bolt right up and will work in the 12V generator…. to a point. The 6V armature wiring is roughly twice as heavy as the 12V. No problem here (except you can’t use a 12V armature in a 6V generator… it’s a one way interchange…. the armature wire size is too small). If you do use the 6V armature for 12V, the generator will only produce about 75%-80% of the amps a 12V armature would. This is because there is one(if I remember correctly) less commutator bar and winding in the 12V armature than in the 6V.
This reduces the amount of amps the generator can produce. Naturally, the voltage rating of the regulator must match the voltage rating of the generator. New voltage regulators for 12V generators are nearly all electronic. Whereas the 6V are all mechanical as far as I can determine. The electronic are not affected by heat or cold, but the mechanical are really affected by heat and cold. The electronic are virtually trouble free. Mechanical units give some problems from time to time and have to be re-adjusted as the springs etc. weaken with age etc.. I wish I could find a 6V electronic one. Anyone out there know of any???? Hope this is of some help to those converting….. rumble seat
Comments
Arrowsmith (Jan 5 2000 2:35PM) RE: 6V generator to 12V
I got mine done at a gen shop on a 47 gen. one of my catalogs have coils I’ll look later today
Terry (Jan 5 2000 2:47PM) RE: 6V generator to 12V
if you have the older type 3 brush generator, it’s capable of 12 volts with just a change in the regulator.
Anonymous (Jan 5 2000 3:01PM) re: Change in regulator
Terry, Since the 3rd brush regulates the output, do you mean that changing it’s position will change the output voltage?
Arrowsmith (Jan 5 2000 3:26PM) RE: 6V generator to 12V
http://www.earlyford.com Early Ford has 12 volt field coils but they don’t say what year The old man that I get parts from said that the Ford early 12v gen are the same size as the 49-53 gen.
CRS (Jan 5 2000 4:02PM) RE: 6V generator to 12V
True. Try 1960 thru 1965 Falcon 12V fields. They bolt up in the flathead case. Use your 6V armature. It’ll work although it won’t put out quite as much amps as a 12V will (about 28 amps). Use the Falcon electronic regulator.
32tom (Jan 5 2000 6:17PM) RE: 6V generator to 12V
the 8ba gen can be converted to 12v by removing the 6v housing and installing a 12v housing off any 57-64 ford. it takes 10 mins. drill a locator hole for mount. it’s easier than changing fields I got my 12v gen for 10 bucks
mr bill (Jan 5 2000 7:23PM) RE: update
I was back at the gen. shop and talked to the guys. They said that by doing something with the brushes that the gen would be able to put out 12V but that the amps start to get to be a problem as they double. I would then have to use only a cut-off and they said that heat can be a problem. It would not work with a regulator. I think that the problem is that I have a 3 brush generator (used only for part of ’38 and then Ford changed to 2 brush) and the 12V field will not fit. I might look for a newer gen. and see if it will work.
Terry (Jan 5 2000 7:55PM) RE: 6V generator to 12V
Bill..shop guys were right. Move the third brush to increase output. Hope their concern about heat isn’t a problem as this is something I was going to try in the spring using a voltage reg made to look like the orig cut-out that sits atop the generator. Directions say be careful not to go above 7-9 amps. other suggestions sound as good or better if original look not a consideration.
CRS (Jan 5 2000 11:23PM) RE: 6V generator to 12V
flatjack: Interesting since the only difference between the 6V and 12V armatures is the 6 volt has one less commutator bar than the 12V. Also the 6V armature has twice the wire size as the 12V. So the 6V will work in a 12V, but not the opposite (it’ll smoke in a hurry). When using the 6V armature on a 12V system the maximum amp charge is reduced by about 20% or so… at least according to rumble seat in a Nov 2 reply. The only thing that has to be changed is the fields. If your 6V case is already chromed, you can change just the fields and retain the chrome case. Otherwise you can just use a 12V case and drill a locator hole for the two ends. The brushes and the brush plates are the same for 6V and 12V.
