The Ford Barn

sunshine · 02-01-2013, 05:35 PM

Has anybody used a pulley that you can attach your fan to such as on a 39 With an alternator , will the bearings hold up in the alt. THANK YOU SUNSHINE

flatheadfan · 02-01-2013, 08:09 PM

Sunshine-

There is no problem running an alternator on a '39 BUT, if you want to run a pulley for a fan on the alternator you will be opening a can of worms. I assuming you are attempting to run a 6 volt alternator. If this is the case you might want to think this through some more.

Obviously, I can't speak for others but, I have tried using 6 volt alternators with a fan and have had poor results. First is the needed activation speed. A quick glance of the family car and you will see the alternator has a small pulley in relation to the engine crank pulley. This is needed to create a high rotational speed to get the alternator to work. If you go with a flathead fan pulley with a large 3'-4" diameter you multiply the needed engine speed exponentially to activate the alternator. From my experience it was about 35-40 mph ('35 Ford w/3.54 rear axle).

In an effort to get around this I made a smaller diameter pulley with a large plate attached that I could bolt a fan to. This did work as planned and did allow for a lower engine speed to get things flowing. However, the fan was spinning so fast at an idle, I was fearful the fan would break-off and cause all sorts of under-hood grief at higher speeds!

If you still want to go with an alternator you may want to abandon the original fan altogether and go with an electrical fan. However, this would require a 12 volt conversion which may complicate your original goal.

The second problem I had with 6 volt alternators is their output. Regardless, of its rating, six volt alternators generally only put out about 38 amps, maximum. This is not much more that a two-brush generator puts out.

As for bearing load, the front end frame of a flathead generator can be grafted on to the alternator housing with minimal problems.

Currently, I am running a 35 amp 2-brush generator on my '35 and '36. No problems, very reliable. If you go with a 2-brush generator and wish to keep a somewhat "original look" under the hood, simply hide the regulator inside the car under the dash.

Hope this helps.

Tom

Andy · 02-01-2013, 09:45 PM

I have a pulley designed to go on a GM alternator and accept a Ford fan. I also have the mount for the alternator to the flathead. $80? Both

miss victoria · 02-02-2013, 10:14 AM

im interested in both can you email pictures? [email protected].

jkeesey · 02-02-2013, 10:39 AM

If you don't get them from Andy, Macs has the parts listed. Complete alternator with mount and fan pulley or you can buy the pulley separately.

John R · 02-02-2013, 10:48 PM

Sponsored Links (Register now to hide all advertisements)

Speedway also lists these parts in their catalog. The alternator pulley with fan mount is P/N 560-10999 ($49.99).

hardtimes · 02-02-2013, 11:39 PM

Hey Tom,
You running a ONE wire alternator? That type takes a little higher rpm to get 'excited' and produce juice, whereas the THREE wire is a different animal and gets its initial startup juice when you turn the key on...therefor...no high rpm start up, and no need for smaller pulley.

02-01-2013, 05:35 PM	#1
sunshine Senior Member Join Date: Feb 2011 Location: SUNSHINE MD. Posts: 318	generator to altenator 39 Has anybody used a pulley that you can attach your fan to such as on a 39 With an alternator , will the bearings hold up in the alt. THANK YOU SUNSHINE

02-01-2013, 08:09 PM	#2
flatheadfan Senior Member Join Date: May 2010 Location: West Michigan Posts: 1,218	Re: generator to altenator 39 Sunshine- There is no problem running an alternator on a '39 BUT, if you want to run a pulley for a fan on the alternator you will be opening a can of worms. I assuming you are attempting to run a 6 volt alternator. If this is the case you might want to think this through some more. Obviously, I can't speak for others but, I have tried using 6 volt alternators with a fan and have had poor results. First is the needed activation speed. A quick glance of the family car and you will see the alternator has a small pulley in relation to the engine crank pulley. This is needed to create a high rotational speed to get the alternator to work. If you go with a flathead fan pulley with a large 3'-4" diameter you multiply the needed engine speed exponentially to activate the alternator. From my experience it was about 35-40 mph ('35 Ford w/3.54 rear axle). In an effort to get around this I made a smaller diameter pulley with a large plate attached that I could bolt a fan to. This did work as planned and did allow for a lower engine speed to get things flowing. However, the fan was spinning so fast at an idle, I was fearful the fan would break-off and cause all sorts of under-hood grief at higher speeds! If you still want to go with an alternator you may want to abandon the original fan altogether and go with an electrical fan. However, this would require a 12 volt conversion which may complicate your original goal. The second problem I had with 6 volt alternators is their output. Regardless, of its rating, six volt alternators generally only put out about 38 amps, maximum. This is not much more that a two-brush generator puts out. As for bearing load, the front end frame of a flathead generator can be grafted on to the alternator housing with minimal problems. Currently, I am running a 35 amp 2-brush generator on my '35 and '36. No problems, very reliable. If you go with a 2-brush generator and wish to keep a somewhat "original look" under the hood, simply hide the regulator inside the car under the dash. Hope this helps. Tom

02-01-2013, 09:45 PM	#3
Andy Senior Member Join Date: May 2010 Location: Kerrville, Tx Posts: 2,771	Re: generator to altenator 39 I have a pulley designed to go on a GM alternator and accept a Ford fan. I also have the mount for the alternator to the flathead. $80? Both

02-02-2013, 10:14 AM	#4
miss victoria Senior Member Join Date: Oct 2011 Posts: 310	Re: generator to altenator 39 im interested in both can you email pictures? [email protected].

02-02-2013, 10:39 AM	#5
jkeesey Senior Member Join Date: Apr 2011 Location: Glenmoore Pa Posts: 1,644	Re: generator to altenator 39 If you don't get them from Andy, Macs has the parts listed. Complete alternator with mount and fan pulley or you can buy the pulley separately.

02-02-2013, 10:48 PM	#6
John R Senior Member Join Date: May 2010 Location: near Washington, DC Posts: 559	Re: generator to altenator 39 Sponsored Links (Register now to hide all advertisements) Speedway also lists these parts in their catalog. The alternator pulley with fan mount is P/N 560-10999 ($49.99). __________________ Those who do not move do not die, but are they not already dead?

02-02-2013, 11:39 PM	#7
hardtimes Senior Member Join Date: May 2010 Location: South California Posts: 6,188	Re: generator to altenator 39 Hey Tom, You running a ONE wire alternator? That type takes a little higher rpm to get 'excited' and produce juice, whereas the THREE wire is a different animal and gets its initial startup juice when you turn the key on...therefor...no high rpm start up, and no need for smaller pulley. Last edited by hardtimes; 02-02-2013 at 11:40 PM. Reason: ......