Packard Forum Index » Modification Discussion

You'll see the original thread i started on the postwar 1946-54 forum, January 14th, 2013. I found a company supplying a 6-volt, positive-ground alternator for old cars, a reworked modern Delco unit, putting out 55 amps at idle, weighing only 9 lbs. The fellow assured me it came with different width pulleys after I repeated, twice, that 1940-50 Packards with the big engine used a one-inch-wide belt. He assured me the biggest pulley he had would handle such a belt (Gates 665, 676; Goodyear, Dayco also offer our 356-ci engine fanbelts).

So i order the alternator and the effing thing has a 3/4-inch pulley. I call the company's 22-year "tech guy" back and he says "the box" or package of pulleys he installs when customers ask for a wide pulley said "one inch."

'Twill be a cold day in hell before i send these numbnuts any business. Meanwhile, i'm good to go otherwise,
as the alternator comes with a universal mounting kit.

I know there are farmers running old tractors, etc.
tho' with six-volt, positive-ground reworked Delco alternators, so our 356 Packards can't be the only things still running using a one-inch-wide fanbelt.

Anyone know a source for such a pulley? The company selling me the reworked Delco 10S or 12S alternator is useless.

Many thanks.

Just curious, why do you feel you need an alternator?

Some GMC and White trucks in the 40s, 50s and 60s used the same belt as the Packard 356 and they all had generators. Maybe try some antique truck vendor parts. Cadillac used a fairly wide belt on the 346 V8 but I don't think it was as wide as Packards.

The 1" wide groove seems to be a difficult find. Have looked at several automotive, farm and commercial sites -- so far without success. 3/4" seems to be about max width in any pulley having the approximate bore and OD needed. The two or three commercial sites that have a wider groove also seem to have a large diameter and bore and a wide hub to go with it.

Which brings up a question on the diameter of the alternator pulley. Am wondering how small in diameter a 1" belt would tolerate before it slips or can't make the bend. The generator pulley is almost 4" but aren't alternator pulleys usually smaller because alternators like a bit more speed? I'll leave that question to someone more versed.

If someone can't come up with info on the correct pulley or if it isn't readily available, am wondering about the possibility of taking the supplied pulley to a machine shop and see if they can duplicate it with the wider groove for a reasonable price. If that could be done maybe someone else might be interested in getting one.

I make a lot of parts for rare cars so I have some idea as to cost. Machining a pulley would cost hundreds of dollars and require a design for the machinist. I suggest you take the pulley you have that fits the alternator shaft and use that hub. Then find a 1" wide pulley of the correct diameter and give them both to a skilled fabricator. They can cut both pulleys apart and weld the 1" wide rim to the hub to give you what you need. Make sure the fabricator is skilled at welding and machining so you do not get something warped. The welded pulley needs to be held in a concentric position for initial tack welding. All this would cost more than a correct pulley but way cheaper than machining from a solid bar.