Somthings just not right with my belt size...

[baginoman]

This is the second time this has happened. I've got my second 76.5" belt (dayco poly cog), and it shredded on me! That's the second one in 5 months! Is the size to small for my set up (sig at the bottom)? I have a 78.5" belt...should i give that a try? And yes, I've looked at the belt sizes page:beer:

 

[venumb]

Do you have the 100mm BILLETFLOW Idler? If so add 1/2 inch to your belt. I had this problem and finally read the whole paragraph on cobrabobs page at the top above the table. After I broke a belt broke, an idler and then snapped my tensioner I finally learned.

If not then just ignore this post! Trying to help you buddy. Nice car too in your sig

 

[baginoman]

yes sir, I've got the 100mm. Thank you:beer:

So i need a 77"?

 

[MaximumVelocity]

Bagino...where is your tensioner positioned with the belt on? Should be somewhere in the middle of its range of travel. If it is almost maxed out, there will be too much tension on it...and under boost, it only gets tighter.

I would check alignment first, this is the primary cause of belt noise/ destruction. I had to make an additional alternator bracket for a KB car because it was twisting the alternator and breaking the front rib off the belt on the dyno. Put the new belt on and blip the throttle while watching the belt over the idlers. If the belt walks forward or backward, there is an alignment or pulley bearing causing problems.

 

[venumb]

So you have the Eaton S/C still...
a 2.76 upper
a 2lb lower
and stock idlers
with the billetflow 100mm upper snub idler?


Please note that the information for this guide was obtained through 3rd party sources so use at your own risk. There are also size overlaps with certain pulley sizes. This Guide should be used as just that -- a guide.

Also, I cannot make recommendations on belt sizes because there are too many configuration possibilities. Thanks for understanding.

If you are using the new Billetflow Idler Bracket you will have to add 1/2" to the belt sizes shown below for your application due to its larger size, except where the configuration already notes a Billetflow bracket.

Note that wherever a 75" belt is recommended that the stock 75.1 belt can be used as well.

FYI -- Stock idlers are 90mm. Belts are 8-rib design.

Also note that some of the belts below may no longer be available. I have been informed, for example, that the Gates K080735 is discontinued, and that the K080733 can be used in place of the K080735.


The closest thing I see to what you need is at the bottom of the chart. 2.75 upper 2lb lower 1-100mm idler and stock alternator pulley.
I'm not sure how you even got a 76.5" belt to fit when it looks like you need between a 77 and a 78" belt. If its a huge pain to get on its most likely too small. I learned the hard way.

Luckily I only went through one belt and when the belt snapped it didn't break anything else. Be careful and make sure you're running the right size. Too small of a belt will wear out the bearings and the idler(s)

 

[venumb]

This is what happened to one of my idlers from running a belt too tight.

I would try to get a Gates or Gatorback. Oreillys sells Gates belts. I tried to avoid the dayco

 

[baginoman]

Thank you everyone, understood.

 

[Greg@RET]

We will be at the shop today if you need some help Joe.

 

[baginoman]

Thanx Greg, i'll let you know if anything :beer:

 

[BBCOBRA]

I'm running the same setup no problems. I've used gatorback and currently using a gates belt. the 76.5 is tight but fits just fine. I wouldn't run any thing bigger than a 77" belt. That will put your tensioner in the middle of its range.

I did have to notch my tensioner to get the 76.5 on there by the way.