Pulley size???

[WHT98GTP]

Hey, does anyone happend to know a way to find out what size a pulley is??? My buddy just gave me on he got for his Boneville andnever used but he cant seem to remember what size it is. Its not stamped anywhere on the damn thing... from looking around the sites, I have determined that its a Thrasher Press-On one.. Just not sure what size. Wanted to see if anyone happends to know how to mesure it? I thinks it may be a 3.4??? Thanks

[Swash]

I believe....just measure from the center of the shaft hole to the outside edge. Numbers like 3.8, 3.4, 3.25 - that is the radius; not circumference of the pulley.


-Swash

[blueguy]

Yup, that's it ^^ Or you can measure your stock pulley all the way across and then measure that one and subtract the difference.

[WHT98GTP]

Sweet. Last thing I wanna do is throw tons of boost at this thing without the proper supporting mods. The pulley doesnt seem much smaller than the stock so i was figuring its a 3.4 or so... And sence its form Thrasher, they only show 3 sizes for sale so...

[WHT98GTP]

... Well that didnt work! LoL From the shaft opening to the edge, it about 1.75. LoL So thats what??? Like 50psi! LoL Man down???

[Swash]

Then....it's a 3.5 pulley.

-Swash

[blueguy]

Well...then it is a 3.5" I'd guess.

[blueguy]

Damnit Shannon...one minute LOL

[WHT98GTP]

Well, I am gonna assume that its a 3.4. Sense fram what i can see, Thrasher doesnt make a 3.5. They only seem to have a 3.4, 3.25 and a 3.0. or so the site sais..

Thrasher Press-On Supercharger Pulleys: 3800 Performance

I guess we'll find out. LoL Thanks Guys, I really do appriciate your input.

[Swash]

Is "Thrasher" etched on the edge?

[WHT98GTP]

You know... its actually not.... Looks just like one of theirs... where the F*&# did this thing come from????

[Swash]

It's probably a Pulley Boys or possibly SLP...just guessing.

-Swash

[WHT98GTP]

Damn... I have to look more into it. Thanks Bud.

[blueguy]

If it looks like s stock one then it could very well be a SLP 3.5" press on.

[Liquifire]

I think the correct way to measure is to take a string and lay it in the groove of the pulley and divide by pi? (3.14 approx) is this right? something like this I have heard of, but not actually doing it myself. You have to be sure to measure from the center of the shaft hole to the edge to get the radius(but where do you measure to as you cant tell where the top of the groove is exactly, you cant measure this to the bottom of the groove is, and if you measure to the lip you will be off as well.........somebody please straighten me out. are the lips all the exact same height on all aftermarket set ups?

[TheOtherNick]

^ that would be the best way imo. And to get a more exact number its 3.1415926535897932384626433832795

[WHT98GTP]

Humm... I dunno. It doesnt look like a stock on, looks identical to the Thrasher Press on. I dunno... Might just get a modular system and call it a day...

[Liquifire]

Humm... I dunno. It doesnt look like a stock on, looks identical to the Thrasher Press on. I dunno... Might just get a modular system and call it a day...

did you find out what size pulley this was for sure?