HELP - how do I get the pulley off of my SN89?!?

[Michael]

Hey guys,

OK, I picked up this SN89 yesterday. I showed it to my brother this morning, and when he went to pick it up to take a closer look at it, he grabbed it by the pulley and the pulley came off in his hands. No problem, I put the pulley back on the output shaft, and HAND TIGHTENED the three allen-head bolts that hold it in place.

NOW I CAN'T GET THE STUPID THING OFF!!!

Any help would be greatly appreciated.

[pavement pounde]

This picture shows my pulley with plastic cover covering the large bolt that holt the pulley.
The pulley and shaft use 2 keys to keep tight, normally you use a puller to get the pulley of.

[speedytang]

Three allen head bolts to hold on the front pulley?
Sorry Lost........

[Michael]

Three allen head bolts to hold on the front pulley?
Sorry Lost........

Hi speedystang.

I'm not surpirsed at your response. The pulley I have is quite different from the one pictured in Pavement Pounder's post. There is no cap and no threaded bolt hole coming out of the center of it. There are six holes around the center hub, three of which are tapped for these allen head bolts (I don't know what the other three are for). When it was off, I looked inside the other end and it looked like it had two half-round shims inside but I couldn't figure out how they held on to the shaft. Like I said, I only put the bolts on finger tight because I knew I'd be removing the pulley anyway. But now with the bolts removed the stupid pulley won't come off!

I will try to take some pics in a while and post them. That will give you a much better idea.

Stay tuned.

[Dirk Diggler]

That does not sound right??? I am curious to see pic's of this setup.

[Michael]

Hi again guys.

OK, here's the pics:

http://i13.photobucket.com/albums/a2.../IMAG00002.jpg

http://i13.photobucket.com/albums/a2.../IMAG00003.jpg

I've never seen a setup like this before, and I'm stumped. I tried again earlier to take it off, but it won't budge. I don't want to put too much force on it for fear of doing damage so I'll wait to hear everyone's feedback. To be honest, I have no idea that this is even the correct pulley for the system.

Thanks again guys!

[SuperL98]

This is a split hub pulley from blowerworks (old carroll supercharging).
When you tighten the bolts (in the picture) it forces the split hub to tighten on the shaft.
You need to full loosen the three allen heads, than find three bolts that thread into the "unused" holes in the pulley.
Tightening these three (new) bolts will pull push the split hub out of the pulley and release the assembly from the shaft.
To re-install, slide assembly onto the shaft and tighten the three original screws evenly to sqeeze the split hub.

[Michael]

This is a split hub pulley from blowerworks (old carroll supercharging).
When you tighten the bolts (in the picture) it forces the split hub to tighten on the shaft.
You need to full loosen the three allen heads, than find three bolts that thread into the "unused" holes in the pulley.
Tightening these three (new) bolts will pull push the split hub out of the pulley and release the assembly from the shaft.
To re-install, slide assembly onto the shaft and tighten the three original screws evenly to sqeeze the split hub.

AWESOME!!! Thanks SuperL98!

Can I use the three bolts that I already have to split the hub, or are the ones that go into the other three holes a different size?

So, does this mean that I actually have one of the original Carroll Supercharging kits? I've contacted Greg at Blower Works about an installation guide ($25). He said that he put more "goodies" in his kits than what he put into the ones sold by Paxton. He said that his installation guide lists all the goodies so that I will be able to tell if I have a genuine Carroll kit or not.

Thanks again SuperL98!

[speedytang]

Interesting pulley but not sure why they(Carroll) went to all that trouble for a pulley other than making sure they limited your pulley size choices.

[SuperL98]

The Bad News - the mounting allen heads are smaller.

The Good News - the extracting holes are 1/4 x 20's and sould be easy to find.

Most of what Blowerworks (Carroll) sells, he list in his catalog.
Losts of other good stuff 2, in pdf format.
Under downloads here.
The pulleys are in there to.
http://www.carrollsupercharging.com/

I've seen both the Carroll and Paxton kits installed on L98 Corvettes, and it appears that the "hard" parts are much the same, brackets, pipes, etc. Greg has more "stuff" available, water injection, added injection controllers, etc. and I think he did more tuning on the memcal's. Not sure Paxton even supplied upgraded chips. I asked a guy that had one (Paxton) at a car show and all he had was an FMU booster on the pressure regulator.

[Michael]

The Bad News - the mounting allen heads are smaller.

CRAP! Too bad.

The Good News - the extracting holes are 1/4 x 20's and sould be easy to find.

Thanks for the thread size. I'll take a look to see what I have here at home. If I don't have 'em, I'll pick them up tomorrow at work.

Most of what Blower Works (Carroll) sells, he list in his catalog. Losts of other good stuff too, in pdf format.

Under downloads here. The pulleys are in there too.
http://www.carrollsupercharging.com/

I've seen both the Carroll and Paxton kits installed on L98 Corvettes, and it appears that the "hard" parts are much the same, brackets, pipes, etc. Greg has more "stuff" available like water injection, added injection controllers, etc. and I think he did more tuning on the Memcal's. Not sure Paxton even supplied upgraded chips. I asked a guy that had one (Paxton) at a car show and all he had was an FMU booster on the pressure regulator.

Thanks for the link. I've actually downloaded most of the .PDF files that Blower Works has available, but I haven't really looked through them yet. I'll do that as soon as I finish with this post.

Thanks again for all the help SuperL98! Greatly appreciated.

BTW - you wouldn't happen to have a copy of the installation instructions that you can scan and email me would you?

[Michael]

Interesting pulley but not sure why they (Carroll) went to all that trouble for a pulley other than making sure they limited your pulley size choices.

Hi speedytang,

I thought the same thing you did with respect to this pulley, but as it turns out Carroll (now Blower Works) offers six different diameter pulleys for the Paxton SN series superchargers - from 3.50"dia to 4.60"dia (in .25" increments).

And the reason they used a taper-lock insert to hold the pulley on the shaft is because the tapered cone insert actually "grabs" the entire shaft when the three bolts are tightened and torqued to spec. According to Carroll, it is far superior to keyway type pulleys.

Freaked me out, though! :laugh:

Although, I gotta ask - with the original SN89 impeller (not the upgraded "pink" impeller) and a 4.25"dia pulley, is there any "real" advantage for me to go with a smaller pulley if I'm just bolting up to a relatively stock 350 TPI motor? Would there be if I were to upgrade the impeller?

[Dirk Diggler]

What the heck is the "pink impeller"? I know they made two styles of impellers for the sn series, one produced 5-6psi, the other 7-8psi. not much difference, just heating the air more Interesting on the pulley keyway.

[pavement pounde]

Still we need to know what you crank pulley size is.

[Michael]

What the heck is the "pink impeller"? I know they made two styles of impellers for the SN series, one produced 5-6psi, the other 7-8psi. not much difference, just heating the air more Interesting on the pulley keyway.

Hi Dirk. Sorry about the confusion. From what I understand, there is an upgraded impeller for the SN89 series of superchargers, available from Paradise Wheels. The I don't know many details about the impeller itself, other than the fact that it ups the boost by about 1.5psi from the original style impeller. It's probably the second impeller you mentioned

The reason why I called it pink is because it's annodized red, but it actually has a pink hue to it. I think Pavement Pounder installed one in his SN93 when he rebuilt it. Here's what it looks like, along side the stock one:

http://photobucket.com/albums/v129/p...d/Pic_0019.jpg

And I agree - that keyway is interesting. I know that split collets are used to hold industrial machine tools like end-mills and stuff, but I've never seen it used on this type of application. But I trust Carroll, they seem to know their stuff.