Mach 1 Vortech Belt Issue

JGDogg10

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Hey guys,
I’ve looked everywhere and read pretty much all the posts with belt shredding issues, but the belt on my Mach 1 keeps shredding off the inner rib. I had two shops work on it and both said the pulleys were aligned correctly but it kept shredding it. I finally got a laser alignment tool and all of the pulleys are dead on. The car has a 15% crank, a 3.15 vortech pulley, a thump racing single bolt tensioner and has been converted over to an 8 rib system. One mechanic said the tensioner could be putting too much pressure on the belt and causing things to strain...I just don’t know where to start and wanted to see if anyone else had any issues with the thump tensioner or where I should even start to look for the next problem area. Will a stock single bolt tensioner work with the 8 rib belt?

Belt size is a 112.4” as well.

Any suggestions would be appreciated
 

Brutal Metal

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Does the belt have any play at all when the car is off? Check to see that your idler pulley spins free with the belt off.
 

DSG2003Mach1

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the pressure of the thump isnt the problem.

Hows the belt riding on the water pump pulley and what did you do with the water pump to accomodate the 8 rib?
I tried using the spacer from the GI Joe kit and never could center the damned thing. I had the outer lip machined off the front of the water pump pulley (radiator side) and that lip cut a rib off my belt.

Also with the Thump Tensioner take it off and look very very closely at the pulley while spinning it - Ive seen several of them that wobble, maybe its walking the belt a little?
 

JGDogg10

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I just followed the instructions from the GI Joe kit for the water pump pulley. Seemed centered and runs straight. My belt is ripping the ribs closest to the block side and if anything it almost looks like the water pump pulley is spaced out further than needed. Did you guys have any play at all in the ribbed idler pulley on the passenger side? With bolt tightened it still has some movement to it. I can’t remember if that was a pulley specific to the 8 rib kit or what can I replace it with? I took pics but they are all too big so I’ll try to resize them and post them up
 

DSG2003Mach1

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I dont recall any play but not sure I really checked either. I don't think I can really judge it until I take the belt off the tensioner again. it should be an 8 rib specific to the kit. Maybe theres a spacer mix up not taking up all the space and allowing it to move? That movement could be walking the belt and eating the rib - I would investigate that further
 

old01cobra

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Im going through this currently also. 10% over drive crank GI joe 8rib conversion etc. I haven't started it because I still need to get the wiring to the fuel pumps done. Its on a 2001 cobra with a FR500 intake. When I turn the car over by hand everything seems like it rids correctly. The lower idler pulled that's on the vortech bracket it was riding right on the outside edge so I spun that idler pulley around and it seems like its running better as its not on the very edge now. However my concern with my setup is if I look at the alternator pulley to the supercharger pulley (v1 ti with 3.1 inch) they don't appear to be aligned 100 percent, its hard to tell but by eye it seems off. But when I turn it over by hand everything appears to be walking properly on the pulleys. JG dog 10 when you get a chance check your idler under the alternator and the alternator too supercharger alignment. Maybe we have similar issues
 

blownstang4.6

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What brand belt? I'm pretty sure the belt on my Mach with 3.125 pulley and stock crank pulley is 113" something. I'd think you'd need a larger belt with the overdrive crank pulley.
 

1996MysticSnake

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Belts too small and your probably not getting enough wrap on one of the pullies and it's jumping ribs.

When you let off at high rpm it unloads the belt and makes the tensioner snap back a little. Bet you that's when is happening.

I have a stock size damper, thump tensioner and 3.33 pulley with a 112.5 belt never once shredded a belt in 6 years.

Sent from my Pixel 3 XL using Tapatalk
 

JGDogg10

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Sorry guys it’s been a while since I’ve been able to work on the car. The belt is a gates HD green belt, and it is 112.4”. I’m going to try to put the belt on the car in about an hour. So you think that I should be using a bigger belt Mystic? Is your car a Mach 1 as well?
 

JGDogg10

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So I finally got around to trying to put everything back together. I ended up buying a stock tensioner to replace my thump racing single bolt(which they no longer make and probably for a good reason) and changed a couple bearings in some of the pulleys. I went to put everything back on and the 112.4” belt is too short now. I didn’t grind the stop off of the new tensioner because I couldn’t remember if I was supposed to do that. I feel like I shouldn’t have to grind it to get the system to work properly, but I’m gonna call vortech on Monday to verify. But I think that the belt might have been too short this whole time and it wasn’t allowing the tensioner to flex when the belt was stretching, so when I let off the gas, the slack from the belt was getting slapped back on too quickly by the aftermarket tensioner and was jumping the belt off the pulleys(just a theory). I’m gonna order the 113.1” belt and see if that will put the tensioner in the proper clocked position. If this ends up working with the stock tensioner, I’ll probably try putting the thump tensioner back on and seeing if it will work as well with the longer belt. Fingers crossed I’d hate to have a $400 paper weight, but at this point if it works with the stock tensioner then I’m all good with that! Lol
 

JGDogg10

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Im going through this currently also. 10% over drive crank GI joe 8rib conversion etc. I haven't started it because I still need to get the wiring to the fuel pumps done. Its on a 2001 cobra with a FR500 intake. When I turn the car over by hand everything seems like it rids correctly. The lower idler pulled that's on the vortech bracket it was riding right on the outside edge so I spun that idler pulley around and it seems like its running better as its not on the very edge now. However my concern with my setup is if I look at the alternator pulley to the supercharger pulley (v1 ti with 3.1 inch) they don't appear to be aligned 100 percent, its hard to tell but by eye it seems off. But when I turn it over by hand everything appears to be walking properly on the pulleys. JG dog 10 when you get a chance check your idler under the alternator and the alternator too supercharger alignment. Maybe we have similar issues

By eyeballing it, my pulleys looked way off too! Especially the alternator to supercharger pulley, but after I got the laser alignment tool on there, they were perfectly in line. The only way to do it is with that tool. I tried the straight edge way as well, but never could get it right. I’m hoping the longer belt will solve my problems.
 

termcobra281

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I agree with the longer belt. I had problems with my eaton doing that... come to find out the supercharger pulley was out of alignment, those things are a pain best of luck you will get it
 

JGDogg10

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Well I got the belt on! I ended up getting a k081131hd. 113.1”. I also took off my thump racing tensioner and put a stock one back on. I had a few people tell me that with the tighter belt and the tensioner being too strong, the belt was possibly getting slack in it and then the tensioner was slapping back too hard and pulling the belt off. I haven’t really tested it to the full extent, but the drive around town went good so far . I’ll keep an update on it and see what happens. I’ll post pics soon.
 

DSG2003Mach1

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My understanding is we can get bad slop between the alternator and power steering pulley. I haven’t had my thump pull the belt off.

There was a guy making a standoff to add an idler on that run. I’m thinking about trying it (nought the stand-off years ago) to take a little slack out of these belts that are a tad too long
 

JGDogg10

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In the last pic you can see where there is kind of a black mark on the back of the belt towards the front of the engine. Maybe like 2 ribs in. Any idea of what could be causing that? It’s obviously one of the smooth pulleys, so an idler, tensioner or water pump... but what could be causing it?
 

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01yellercobra

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In the last pic you can see where there is kind of a black mark on the back of the belt towards the front of the engine. Maybe like 2 ribs in. Any idea of what could be causing that? It’s obviously one of the smooth pulleys, so an idler, tensioner or water pump... but what could be causing it?

My first guess would be that idler missing paint. Are those rub marks on the spacer that goes under the alternator?
 

JGDogg10

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Well the belt ripped a rib off and jumped forward on a few of the pulleys again. I drove it around cruising and everything was all good. On the way home last night I decided to try to get on it a little bit and see what would happen and it’s pretty clear that what I changed didn’t fix the problem.. Obviously my laser alignment didn’t work or something. I’ll take some pictures in a little bit.....

DSG, The radiator hose was pulled up for extra room installing the piping and supercharger. It doesn’t stay like that! Lol
 

DSG2003Mach1

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Well the belt ripped a rib off and jumped forward on a few of the pulleys again. I drove it around cruising and everything was all good. On the way home last night I decided to try to get on it a little bit and see what would happen and it’s pretty clear that what I changed didn’t fix the problem.. Obviously my laser alignment didn’t work or something. I’ll take some pictures in a little bit.....

DSG, The radiator hose was pulled up for extra room installing the piping and supercharger. It doesn’t stay like that! Lol

that shit is so frustrating... I had a local shop align all my stuff, I dont have the time or patience. I lost 1 rib on 1 belt since then but it was from a sharp edge where I had the lip taken off my 8 rib water pump pulley.
 

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