It seems I'm stuck on the Novi project untill I can get the damn belt to stop walking off the idler pulleys.

I have the pulleys aligned so they are damn near perfect. I can run a straight edge across the blower and crank pulley and they look dead on. The belt walks off the idlers still. Right now this is while cranking the engine over, not even with the engine running. I've tried shimming the spacers to the blower bracket and just made the belt walk off in the other direction. Cant seem to find a happy medium.

The pulleys on the the idler and tensioner are flat, no flange. Will getting flanged pulleys help the situation any or am I barking up the wrong tree?

There doesn't seem to be any bracket flex, nothing is binding. The crank pulley has a VERY slight wobble but that doesn't seem to be it. I am at a loss as to what to check next. Is there a better way to check the alignment other that to just run a straight edge against the pulleys? Any other measurements I can make to get this thing properly aligned?

This is the only thing left to get her running. Any thoughts, ideas, comments, anything at all that may help, would be greatly appreciated.

 

I have noticed that the kit blowers use idlers with flanges on the idler pulley and in cases where they dont the idler is usually close to another pulley. anywhere that the belt has a long length an idler should be there to reduce the rubber band/guitar string like motion that forms in the belt.

 

Sounds like your idlers or something related to them are flexing or loose. Also, I don't know what belt setup you're using, but most multi rib belts need a dynamic tensioner or they will come loose.

 

Can someone measure the diameter of the ATI idler pulleys?

All the idlers are rock solid, no flex, straight, turn smooth. I'm using an automatic tensioner from an unknown application, guy at the parts store let me rummage around through the tensioners
I'm thinking I'll add another idler to the lower stretch of belt, and replace all the idlers with flanged pulley's. Does anyone know of a source other than ATI for pulley's? All the local parts stores are useless, the closest I came was Napa, but they have nothing flanged in an 8 rib. Cant find anything online either. Hate to spend $80 a piece for the ATI's and not have it fixed.

Anyone upgrade to 12 rib and still have their 8 ribs around?

 

Mark,

I don't know if this is any help, but the idlers on my ATI system are a bit bigger than the belt (approx 3/8") the belt doesn't even come close to the edges. both Willie and i had alot of belt troubles, and we both ended up shimming the bracket out.

later
larry

 

After you shimmed the bracket out was the blower pulley sitting out farther than the crank pulley? Did you have to shim it out evenly on all spacers or did you have it slightly cocked? Just how does the blower pulley sit in relation to the crank pulley? ANY info at all on this would be helpful as this is the last hurdle to get it fired up and running.

Also if anyone can give me exact specs, diameter and length across, on the ATI pulleys it would be very helpful. I need to figure out if the pulley will fit my tensioner.

 

http://www.aspracing.com/intro.htm

they can make anything you want, & they are reasonable, considering they are doing one off custom work.

BW

 

Mark,
To answer your question, No i didn't shim evenly, so yes the bracket is kinda cocked, i used a .030" flat washer and it worked great. I'll attach a pic, it's kinda hard to see the bolt hole in the bracket, but you should get the idea.


later
larry

 

not to get off subject too much but do you think a guy could flip a procharger bracket over and mirror image install it on the other side using a spacer and deleting the A/C, Smog pump, and the ac/smogpump bracket??

 

B4Ctom1
Only issue I see in moving the unit to the passenger side is that the outlet on the head unit would be facing the wrong way. Other than that, I see no reason why it wouldn't be possible.

 

I figured a "reclocking" of the outlet on the back would make it match the way it was on the other side. Im not saying I am going to do it. I might just keep it where it is with a spacer and do away with all the assy brackets and run only a alt. on a low mount. Im reducing clutter to improve serviceability. and weight.

 

Finally back on track with this again! I hate my job. Anyhow, I'm looking at adding an additional pulley or 2 to eliminate the long streches of belt I have now. Could someone measure the distances between pulleys? Need to know just how long a stretch of belt I can get away with if this is indeed the problem. Am I right that ATI added an idler with the D1 kits? Any idea why?

Now that the snow is flying I can really concentrate on getting this thing right without the itch to drive it.

 

bringing this way back from the dead, however, just wanted to give my feed back for others in the future that use the search function.

I just installed my P1SC kit and it was walking to the back of the crank pulley, so I did as suggested above but shimmed the lower of the two bolts, because I was having the opposite problem.
I used a .020 brass shim.
It appears to have done the trick!

Thanks all of you guys for the info!