Custom length Supercharger Serpentine belt
 

Would anyone know if it's possible to get a custom length 8 rib Micro V serpentine belt. I need one of the following spec: 8PK530, the 530 means 530mm long (21").
This is so I can run a 2.80" SC pulley on my Air to Air modified Stillen SC kit to be able to get the belt tight enough. If not I'll have to purchase and install a different combination of pulleys which I'm really trying to avoid.
I have already made a number of enquiries and looked around on the web but no luck so far. :(

The answer is yes, but it will cost you. I contacted Gates about converting a eight to a seven rib for the main belt to accommodate the additional pulley to get more wrap for the SC jackshaft. They told me it would be a $10,000 set up fee and I would need to order 100 units.

I wound up converting the eight to a seven rib by cutting off one rib using a utility knife. Took about ten minutes to do.

You can go to the Gates web site and research it.

Good luck.

You can change the idler pulley for about $40 and that will take up the slack. The NAPA part number is here on the forum. If you can't find it I can.

You sure on the pt.# ?
Also the length?
I normally use napa for belts & that number would be a 25-080530,,,just over 53" long,
i see you stated 21"

Will this work? KT38-G-500KW Cummins Generator belt

I've seen numerous applications @work on off road eq....I just don't have the parts manuals available....23,24" is the lowest i'm finding
"Brain-Teaser"

Thanks SouthArk370Z, I've just sent them a message to try and find out.:tiphat:

Thanks jchammond, yes it's a real "brain teaser" :ugh2:

They don't offer a cogged set of pulleys w/belt?
Also, don't rule out a 10,12,14 rib & cutting to fit; also could run a pair of 4's...pending they're sturdy enough.

Thanks TBatt, Lol at doing a proper tooling and production setup but interesting to know re Gates.
What is the "additional" pulley you are referring to and how does going from an 8 to 7 rib fix anything? Do you mean the serp belt on the engine side that drives everything? Is the main drive serpentine belt (OEM) 6 or 7 rib? I thought the serp side pulley (opposite 8 rib jackshaft pulley was 6 rib):confused:
Is it correct that 7 (rib) belt is the right fit for a 6 (groove) pulley? Therefore the belt always has 1 more rib than the grooves on the pulley? So you would get a 6 (groove) pulley to suit a 7 (rib) serp belt? This has utterly confused me.
Sorry I'm old ;)

The main serp belt is a 7 rib. Stillen supplies a seven rib in their kit that works for the stock setup. On the SC mounting bracket, Stillen includes a threaded hole for an additional pulley to help with the belt wrap around the jackshaft drive pulley. The only belt, that I could find, that was the proper length is an eight rib belt. That is the belt I went with and simply cut off one of the ribs.

On the SC side we have an eight rib belt. If you use a 2.9 inch SC drive pulley you will not have enough adjustment of the idler pulley to prevent belt slip. What we have done is to replace the SC side idler pulley with a larger diameter idler which takes up more of the slack and allows you to get proper belt tension. As an added bonus the larger idler allows for more belt wrap around both the jackshaft and SC pulleys.

For more info check this out: http://www.the370z.com/forced-induct...-member-9.html

Thanks for that great info TBatt :tiphat:

I used the NAPA pulley that Pauly Z found for us:
Pulley- 54 mm #36375
Belt- Micro V 6 rib #061093 OR MODIFIED K081088 along with a 12x1.75x50mm bolt, a 12x1.75mm hex nut and 6ea. 7/16 inch washers for spacers. I had to make a spacer to make up the difference between the inside diameter of the pulley and the 12mm bolt. A step up shank bolt would be best but you use what you have available. If you need a spacer let me know and I can make one for you. I may just go ahead and design a step spacer so that I don't have to use all of the washers. Let me see how it fits and then I can go from there on the design.

The belt cut down will happen tomorrow night (the wife has plans for me tonight). The belt I got is the fleet HD belt so it should hold up well. The bad part is that it is green........Heck as long as it doesn't slip I don't care what color it is!

I checked the K080188 eight rib belt last night and the rib size and spacing is exactly like the K071045 (stock Stillen) belt so removing one rib will make the correct belt for us at the 109 3/8 length. This is way cheaper than the $10K setup fee and 100 minimum buy from Gates.

As mentioned in my last post, I did design a custom step spacer for mounting this additional idler pulley. This spacer sets the correct spacing with out using a stack of washers and eliminates having to have a spacer to fill the gap that results in having a 12mm bolt in a 14mm bearing.

I have one of these spacers on my car and one other forum member has one and another will be made and sent this weekend. Let me know if you need one.

I'll post some pictures when I get it made and show how it works. I also have a detailed drawing that I'm willing to share so that you can make your own.

Very decent of you TBatt!:happydance: