pulley problems*

[greatdane]

My wtr pump pulley is hitting my alt bracket!? My crank pulley doesn't fit over the balancer bolt, don't some of them? I bought them of slez bay they are suppose to fit my application lwp sbc! I may need to shim it out at least a 1/4" to clear is that normal?

[Captkaos]

The crankshaft pulley doesn't go over the bolt.  The pulley goes on the balancer first and then the bolt is installed.

Were all the pieces bought as a kit?

[greatdane]

The crankshaft pulley doesn't go over the bolt.  The pulley goes on the balancer first and then the bolt is installed.

Were all the pieces bought as a kit?

No, I pieced it together! The engine builder installed the balancer then I ordered pulleys and alt bracket later..... I think I can shave a little of my alt bracket to clear the wtr pump pulley! What does that balancer bolt torque at?

[greatdane]

Got my stock pulley out of my other garage today. I realized that it is smaller in diameter than the aluminum one I bought. So I guess I need a different wtr pump pulley! The one I bought was suppose to fit a 69 and up sbc guess not...

[greatdane]

OK here is my next question! What diameter should you crank pulley be on a 82 sbc? The one I bought is much smaller in diameter than the old stock one! It bolts up though....

[rwhit57]

My crank pulleys are 7-3/4" measuring across the face. I would think a smaller one would not be a good idea.

[Swims350]

smaller/larger is where you get into underdrive pulleys and overdrive. I don't think it'd matter much as long as they fit. I do know summit has measuements listed on their chrome pulleys so might want to check with them. May have to order some other ones or just run some painted stockers for now. I got some mismatched crap that I have no idea what they came from, a 3 groove wp and 3 groove crank pulley. I have no idea what they came from, there were several motors around at the time a couple straight 6's a 305 from an 80ish el camino and a 350 that was in a chevy truck, but was stock from a 74 c20. Has a new water pump on it but I have no clue what pulley came from what.

[greatdane]

My crank pulleys are 7-3/4" measuring across the face. I would think a smaller one would not be a good idea.

I wonder what it would matter? I think the one I have is for a earlier sbc like a 69 or so. My stock one is bigger around I think 7-3/4" this one is 6-3/4"....

[Swims350]

Think of it as the cogs/gears on a bicycle. big one in front, little one in back or different sizes in the back and think of how the effect the tire speed/rotation. One way you have let's say a whole rotation on the crank to one rotation on the tire, and with a different size cog you'd have 2 turns on the pedals to one of the tire or vice versa, thus making underdrive or overdrive.

Basically one way the crank is going to not turn the accessories or maybe just the water pump as fast or as much as it should be, and the other would turn it more. I got mixed up on info lke that alot so that's why I haven't said well the big pulley will do this and the small one this... cuz i get confused on what one does what. I would think if you put a smaller one on the wp and smaller one on the crank they'd balance out, or if you done bigger on both.

[greatdane]

So if it is 1" smaller diameter than stock will it hurt anything? Also the new one is two groves were the stock was 3! I am not running a/c yet.....

[jaredts]

The smaller crank pulley will turn the accessories a little more slowly which consumes less power from your motor.  People intentionally do this all the time.  The only thing that I would think to watch for would be that the alternator charges adequately at idle.  People do it though so it must work.  Also not sure where you are measuring.  If you're measuring the outside flange it could be misleading.  You could put a belt in the groove and measure the outside diameter on the belt and do the same with your old one to see if there's really a difference.

[Swims350]

my summit catalog has the measures in it for theirs and they are all under 7 inches they are like 6.60 and such or smaller. That's for chrome or billet.

[greatdane]

Ya thats all I found also? I think I am OK!

[Layne]

I have underdrive pulleys on my 88 sierra and had them on my 77. I had to bump the idle up to 850 on the 77 too keep a good charge. My seirra has no problems whatsoever. You'll be ok, just check your voltage at idle