weiand 671 blower belt issue
 

we are working on a 1937 chevy truck with a highly modified 350 with a weiand 671 blower. problem is no matter what we do with the idler/ tensioner pulley the belt goes forward on the pulleys until it is stopped by the shoulder of the idler pulley. it acts like if we let it that it would walk all the way off the pulleys,,,,, any ideas what the problem could be ????

671 blower belt issue
 

we already replaced the bearing just to make sure, same thing still happens

belt walk
 

I have some leftover parts from a 6-71 I would get rid of if you wanted them. Tom 270-556-5340 [email protected]

Ya might check your intake also to make sure it's square. I had one that had a slight taper front to back that caused the same problem. A good machine shop can fix it.

TS1955

X2 and you may have a head milled with a front to back taper. That would make everything out of line.

Walking Idler pulley ?
 

Assuming the heads, block, crank,ect are true . The only thing that will make the belt run off is the Idler pulley ! The belt will walk to the tightest side of the pulley . I took the spacer behind the pulley and used a fly cutter to take .030 off . This put a angle on one end of spacer and flat on the other end that goes up againist the inner race of bearing , this will let you change the angle of the idler pulley too make belt true . I'm a machinist , and it took a couple of try's too get it right You will also need to do the same thing to the washer or spacer on the backside of pulley bracket with the same angle you have on the spacer that you just cut ! Unfortantly blower manufactors are not belt people . :D Like the other guy said bearings must be good or you will never get it right ! Also , turning the belt around , or replacing does not work ,belt will still walk towards the tight end of pulley ! Hope this helps . . . . . YOU CAN EMAIL ME IF YOU NEED MORE INFO !