The two alternators in the picture are for a 39 deluxe and a 46. I have one just like the ones in the picture on my 39 pick up with a Ford threaded pulley with the fan on it. I also have one in the 35 roadster and used the Offenhouser threaded pulley adaptor. I was a little concerned that there is no fan blades on the Offenhouser one but in 95 degree temperatures the two internal fans in the alternator kept it cool. Surface temperature was less than 150. I wouldn't use this adaptor on a generator or alternator without internal fans, I think it would run to hot. G.M.
generator pulley (fan mount)
- Thread starter V8Barn
- Start date
Here's a few more threaded pulley pictures. One is of the 39 pick up with a threaded pulley on a 2 brush generator with an industrial fan I modified. This truck now has one of my alternators and looks the same. The other picture is when I had a Delco alternator on my 39 convertible but didn't like the looks. This worked good after installing a 24 volt stator. I couldn't find a threaded pulley except this dual truck one and machined the extra "V" off. Before installing the 24 volt stator it wasn't as good as the generator. Notice both have standard Ford pulleys and charge at idle. I wouldn't use the small pulleys most alternators use there is not enough bite on the pulley to run it without over tightening it. G.M.
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flatheadfan
Well-known member
I don't know if this will remove the "fog" surrounding screw-on pulleys for 2 brush generators that have a fan mount. I have three such 2 brush generators with screw-on pulleys. The pulleys have the part number 78-10130 clearly labeled on the pulley. Each one has a locking nut. On one of the generators a hole for a safety wire was drilled which appears to be of factory origin. There was no wire in the hole (probably left out from a previous rebuild). However, when I rebuilt the generator I put everything back together as found and added the wire.
Tom
Tom
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flatheadfan
Well-known member
One more thing. If you look closely at the center picture you will see the fan mounts are closer to the pulley edge than the other two. I suspect this is some sort special pulley for low speed output. None of the three had a suffix to the basic part number 78-10130.
Tom
Tom
I noticed the pulley size of the center pulley right away. That one is harder to find and is the smallest available. I have seen at least 3 differant diameters of threaded pulleys with the fan mounting boss and it seems larger trucks have even larger pulleys then the ones shown above. Alternators need the one in the middle which is the smallest diameter to to turn the alternator faster and charge at idle. I even bought complete generators on ebay just to get the pulleys. Anyone using the Delco alternator needs the small pilley and a 24 volt stator to make them charge at low RPMs and at idle and have a large enough contact surface over the top of the pulley the drive the generator or alternator without haveing to over tighten the belt. G.M.
