I just got a new alternator and no matter how murch force i use, i can't get the pulley off of the new alternator off. The reason i want to take it off is because i have the 2 piece March pullies and the one that is suppossed to go on the alt. is a tiny bit bigger. So i just said screw it, and left the original pullie on the alt. Will this cause any charging problems?

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Mods:Hooker Aerochamber 3" exhaust, gutted kitty,
March 2 piece underdrive pullies, smog pump gone,;these two made a very noticable difference.
14x4 K&N open air element filter-the best mod so far
Eibach springs with KYB's all around.
Appearance: Harwood cowl hood, Z-28 wing, painted black(7/20/00)-original color was light blue
*All these mods were made this year
Stock Options:117,000 miles on motor, 5spd, TBI, 305, T-tops
Run a best of 16.7 @85mph with traction problem. Have to try again sometime.

 

If the alternator pulley is larger...it is an underdrive pulley and will further reduce charging. You need a smaller pulley.

To get the pulley off, you need an air-impact wrench. Take it off to any shop and they'll remove it for you.

But, if you are concerned about charging, that larger alternator pulley will cause you more problems.

FYI, my pullies came the same as yours, smaller (underdrive) crank pulley and larger (underdrive) alternator pulley. I tried it with just the crank pulley first and it works fine. Only on a dark rainy night with the rear window defroster on does the charging fall below 13 volts when idling. All other times it puts out 13+ volts. I have had it like this for over 6 years.

 

Then why the heck woul March give us a larger pully for the alternator if it doesn't do anything performance wise and doesn't help with charging? I would think the larger the pullie is on the alternator, the faster the alternator is going to spin, therefor releasing more charge.

But i'm not gonna bother, i'm just gonna leave the stock one on there, got no problems with it so far.

 

You need an impact wrench to get the pulley off.

 

The smaller the pulley the more revolutions that it is required to do in order to go through the total length of belt. Sort of why bigger tires will mess with your speedo... so, if you have a smaller pulley, it'll have to spin faster so that you get more power out of the alternator. I've heard that a lot of the reason why they give you the larger alternator pulley and a smaller crank pulley is because they want to reduce the amount of belt lash, which will lead to a loss of power.

I'm not sure exactly if that is true or not, I don't use pulleys. I've heard both good and bad things about pulleys. Some people have said that it will increase horsepower, which I never really understood, while others say that it just makes the car react quicker, that seems more logical.

I would think that putting on the shorter crank pulley with the regular alternator pulley would make for a pretty kick *** combination if you can find a belt that will fit it...

-=-Mike



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1989 RS.. Newly installed 350,bored out 30 over, Hypereutectic pistons, double roller cam, double roller timing chain, accel wires, blue streak cap and rotor, platinum plugs, chevy caprice 350 chip.

 

This is why you have to investigate which type of pulley system you are really getting. Some 3 pulley system give you the option of either further underdriving the alternator with a larger pulley (for a bit more power) or overdriving the alternator with a smaller pulley to keep the charging the same with the underdriven crank pulley.

Racers like to further underdrive their alternators because at really high rpms, they don't care about charging but want every HP they can squeeze out.

As you said, just go with the smaller crank pulley. It is all you really need for the street while retaining your charging capabilities (except at idle with all your accessories on).

 

On the HP issue, pulleys by themselves do not create more HP. They just decrease parasitic loss to the waterpump, A/C, AIR pump, alternator and power steering pump, and allow it to be available to the rear wheels where you want it.