Why did i break the belt?(single belt)

[5.0 Hatch]

My belt was new with about 50 miles on it. I drove it last week for awhile without a problem. Then yesterday i put a f-150 pulley on and went for a spin. About 1/2 mile down the road it broke the belt. I hadn't even gotten on it yet.

I had the belt pretty tight, could that cause it to break? What else could have done it?? should i be running a cobra w/p pulley with the f-150 pulley? I have a pretty good gap between the two.

[5150 LX]

Was there any noticeable wear prior to installing the F-150 pulley?

[root]

Check the grooves in the F150 pulley, if one is rough it could have cut the belt...

Ian

[5.0 Hatch]

I checked the grooves and all is well there. And no the belt looked brand new and only had 50 miles on it are so. Would over tightening it cause it to break? Oh and it didnt break in half just pretty much shreaded itself away. I was using one of those elcheapo autozone jobs... i'm heading to napa in the morning and try to get a different brand belt. I'm dying to feel the difference with the f-150/2.75" powerpipe combo. I think with the new belt i'll crank it up and let it idle for awhile and see if maybe its walking itself on the edge of a pulley are something.

One more thing what is the purpose of running the cobra w/p pulley with the f-150 pulley?

[root]

Well if the pulleys are not lined up it can jump off and the edge of the pulley will turn it into cheese strings.. Check alignment to make sure it is perfect.

The purpose of a Cobra pulley is to give you more room between the crank and WP pulley.

Ian

[Goliath5.0]

Also make sure you have the correct belt length... take into consideration the legnth of the belt after it stretches... If it is too long it will slip under acceleration.

Also check to make sure (as Ian said) that ALL of the pullies are lined up correctly.

Also remember to loosen the arbor nut FIRST before you make any tightening adjustments, you could mess up the arbor tensioning system (stud and adjuster) if you fail to loosen the arbor nut (in front of the tensioner pulley) first before any adjustment, then after all adjustments (tightening) is complete, tighten the nut up but do not OVER tighten it... you can strip the threads of the arbor stud. Which I did a number of times!!!

My solution was to get a Novi 2000 arbor stud in place of the Novi 1000 arbor stud, whereas the Novi 2000 arbor stud has MORE threads so the nut can seat better versus the Novi 1000's arbor stud.

(This is for the SINGLE BELT SYSTEM)


-Chris

[5.0 Hatch]

great information guys... the problem was my pullies were not lined up correctly. I put some washers and took measurements for over 2 hours to get everything perfect. All is well and I was able to make it to the track. ran 12.60s@114mph. I think my fmu is killing my power, last time i went to the track i ran 4 degrees less timing and the stock crank pulley and did 112mph WITHOUT running the fmu.

anyway thanks again, oh btw i did notice that the tensioner setup sucks and it seems like it would strip or break easy.