Alternator with a pulley at both ends

I'm sure I've seen this before, but I can't remember where. I'm looking for an alternator on which the shaft extends past the rear of the alternator, so a pulley or another accessorie can be mounted to it. I seem to remember seeing a setup where the power steering pump was attached to the back of the alternator.

Did I imagine this, or was it a custom setup?

Someone here must know?

My Hino had a power steering pump attached to the back. Pretty sure the Isuzu trucks used the same setup. But only one drive pulley, and not really sure why you would have two or how it would be driven. Big and heavy by the way.

Wow, never heard of that before. Can't imagine it couldn't be done, but I've not seen it.

Racemate makes an alternator/water pump combo. Not what you're looking for, but may help?

Thanks bearmtnmartin. The Isuzu trucks have a vacuum pump that's attached to the back of the alternator. This is what I remembered.

I want to add a supercharger to my current built, but I have room for the alternator, or the surpercharger, but not both. But I do have room behind the alternator. So my plan is to drive the supercharger from the back of the alternator. I'd put a pulley on the back of the alternator, and run a belt to the supercharger, using the alternator to provide tension to both the front and rear belts. Thing is, I don't know if those alternators have rear bearings that are big enough to deal with the radial loads from a second pulley in the back. Those little vacuum pumps/PS pump must not put a lot of radial load on the bearings.

I have seen a racecar with the alternator driven off the driveshaft. He sandwiched a pulley between the diff input and the last u joint.

1957 Chevys (and possibly other GM cars of the era) had the generator and power steering pump mounted in series:

Long shot: if the engine is OHC you could copy GM/Fiat and drive the alternator off the back of one camshaft. Then drive the S/C off the crank. In this pic you can see the P/S pump driven off the back of the intake cam.

I can't find a pic, but I once saw a Fiat motor with the air pump driven off the back of the cam on the exhaust side. I believe it was in a Lancia Beta.

EDIT: Found a pic, yes it was a Lancia motor. You can see the drive pin on the back of the left side camshaft.

bearmtnmartin wrote: I have seen a racecar with the alternator driven off the driveshaft. He sandwiched a pulley between the diff input and the last u joint.

That'll work fine for a car that doesn't spend much time stopped or at low speeds

Another possibility: Get an electric water pump, put the SC in place of the water pump?

Or Turbo instead of SC? Turbo is better for most uses.

EDIT: Or electric PS pump and put the SC there?

in reply to Curmudgeon: You don't have to go that exotic. The ford duratec V6 has its water pump driven from the back of one of its camshaft. On the first gen (on contour), it was driven by a tiny belt. Had one, changed the water pump. POS.

But this is for my flathead 6 powered speedster, so that's not a possibility. But I think stuart in mn might have a winner. It would even respect the vintage look, yet be 12V.

Thanks guys.

Electric supercharger?

Audi ran the P/S pump off of the back of one of the camshafts on the rally engines.

Then they went and ran the alternator off of a hydraulic motor, all mounted in the back of the car.

Curmudgeon wrote: Long shot: if the engine is OHC you could copy GM/Fiat and drive the alternator off the back of one camshaft. Then drive the S/C off the crank. In this pic you can see the P/S pump driven off the back of the intake cam. I can't find a pic, but I once saw a Fiat motor with the air pump driven off the back of the cam on the exhaust side. I believe it was in a Lancia Beta. EDIT: Found a pic, yes it was a Lancia motor. You can see the drive pin on the back of the left side camshaft.

The Peugeot 405 Mi16 has the power steering driven off the camshaft.

Air cooled VW had the cooling fan on the back f the alternator.

Early carb 2.2 chryslers had the air pump driven off the back of the cam.

Kenny_McCormic wrote: Air cooled VW had the cooling fan on the back f the alternator.

True. The early cars had generators, around 1975? 1976? they went to alternators which had the same layout.

By the way, I have no idea how I missed your project at the outset. That is really cool!

Also, I don't know if you have considered it but a 'blower Bentley' setup might be worth a look, for the cool factor if nothing else.

Same idea on a small block Chevy:

just remember one thing with the fiat engines. If the pump ever seizes, it will put drag on the cam.. possibly enough to make it jump a few teeth on the cambelt and if the engine is interference....

Fiat learned that one the hard way

For your flathead what if you mount the supercharger to the top of the engine, with the snout of the supercharger alongside the water pump? Might need an idler to get the belt around the rest of your parts, but that's not a huge deal.

Alternately, what about driving the alternator directly from the crank via a shaft, ala the crank to start shaft?

didn't some cars have the supercharge mounted -ahead- of the engine, directly driven off of the crank?

^That's what the "Bentley Blower" setup is. Nothing remotely modern uses that though. It's also heavy because a gearbox weighs more than a belt and a couple of pulleys.

Forgive my ignorance of superchargers, but do you have to have a gearbox? Is there a reason it couldn't be run by a fairly simple straight driveshaft, or even a spider/chain coupling?

A quck Google shows spider couplings with a max speed rating of 8k RPM are readily available.

I once had a forklift that had a power steering pump piggybacked off the alternator, A rebuild shop run by anyone named "Gus" should be able to help.

The supercharger straight off the pulley (ala blower Bentley) was my first idea, but I'd have no more room for the radiator, and I thought the plumbing would get too complicated. Also, as others have pointed, you ideally need to have a gearbox, or a really big CC supercharger to provide enough volume of air. Most OEM SC applications have a reduction of about 2/3.

The VW alternator might be another good option. I'll have to start checking eBay, for potentials.

If anyone, has another possible candidate, plz don't be shy.

Curmudgeon wrote: Forgive my ignorance of superchargers, but do you have to have a gearbox? Is there a reason it couldn't be run by a fairly simple straight driveshaft, or even a spider/chain coupling? A quck Google shows spider couplings with a max speed rating of 8k RPM are readily available.

I believe you're limited to one atmosphere of boost, or something like that.

You need to over drive a blower to make it worth your wild