The Stovebolt Site Forums The Shop Area The Electrical Bay Alternator pulley: 2 different widths?

On a 64 L6 230ci. Since it’s electrical related, I posted here.
Have two alternator pulleys. Both are off 230ci engines. Both are same diameter and shaft size. One is a normal pulley width with cooling fan flush up against the back of the pulley. The other has a ‘spacer’ of about 1/2” from back of pulley to cooling fan. Why is the question. I ‘think’, at one time, one motor must have had another pulley set inside the water pump and crank pulleys. All the measurements such as mounting holes for lower alternator bracket to front of block etc. are the same. Alternators are the same. Anyone have a clue.
One more question please. Does the top bracket, with the slot for belt adjustment, go in front or behind the alternator mounting ‘ear’? No picture of it in repair manual.
Thanks.

Some alternators have a double groove pulley, while others might just have the single groove with an un-machined space where the second groove would usually be. Then there's a bunch of aftermarket pulleys available with a wide groove for farm equipment applications or adapting a old wide-belt stovebolt engine with an OEM generator to an alternator conversion. BTW, the pulley and the fan are separate units- - - -once the nut is removed, they can be separated, so any pulley you want can be added. All you need is an impact wrench. Friction alone drives the armature- - - -there's no keyway in the pulley or the shaft.

The adjuster bracket can fit on either side of the housing ear, but it might interfere with the fan if it's placed in front.
Jerry

My nephew, who is doing this work tells me the alternator pulley lacks going forward a tad to line up with the water pump pulley. The one he had rebuilt for the truck has the smaller width pulley on it. I will replace it with the wider one when I get back to the lake house next week. He is a newbie at this stuff and I finally got into his head, “It will be just fine as long as it’s perfect”.
Thanks for the help.

There are shims available to correct pulley spacing if necessary. I believe I've seen them listed on Ebay. You're right about getting "close enough" though! Depending on the distance between pulleys, I've run belts with 1/8" or slightly more misalignment without any problems.
Jerry

Very familiar with this problem......The rocket scientist who owned my truck before me, destroyed the lower cast iron bracket which holds the alternator. He cut it with a dye grinder & drilled holes in it to move the bracket forward so the alternator would come close in alignment with the water pump & crank....It took a bit of doing to find a replacement bracket. I then took the alternator to an old established electrical shop who rebuilds light & heavy duty starters & alternators....The shop gave me a rebuilt unit, with the correct pulley, without any spacers....We had a good chuckle on how much time & effort was put into trying to make a $10. used alternator to work....(barely). This is just one example when simple trucks like these, fall into the wrong hands......

All is good the the truck pulleys. We got it started for the first time yesterday. Only small problems were leaking fuel pump (new but off shore built), wrong exhaust donut, and off course, paint smoke (he painted everything). What is left is adjustment of B carb. I’ll post that as another question. Thanks.