FYI: belt length for 6lb lower with alt pulley

[adonis]

I've had some trouble finding the proper belt size for use with metco's 6lb lower pulley and alternator pulley for use with 6-8lb lower.
The instructions that come with the 6lb lower recommend a 79inch long belt. This will probably only work with the stock alternator pulley. The 79 inch belt will not fit with the oversized alternator pulley. I first used an 82.5 inch long belt (all I could get at the parts store on short notice). This belt will work but it seems like there is some slipping at high load/RPM. I have tried a few belts and found the 81-5/8" to be the best fit. It's short enough that it's a little tricky to get on. The trick is to put the belt on all pulleys, but leave it off of the idler between the supercharger and the alternator. The smooth idler pulley lets you slip the belt on where the ridged pulleys would need more slack to get it on there. With this belt the tensioner is almost hitting the stop on the 'tight' end. It will probably stretch a little with time.

 

[adonis]

Forgot to mention. This belt length is with the idler near the lower pulley in the upper position.

With the 6lb pulley the idler almost touches the lower pulley when it's in the lower position. You can't even get the belt on/off with the idler in the lower position. I bet with the 8lbs lower you can't fit the idler in the lower position at all.

 

[HIGH ROLLER]

For a short time i ran the 8 pound lower with the metco alternator pulley and the proper size belt for that was 080820 so i would think the 080800 would be pretty close for a 6 pound lower.