Kevlar v belts

[mobileaudio25]

my malibu is throwing belts at high rpm. I drove it today and didn't notice the belt was thrown until my temp gauge said 250. It didn't break it just threw it.

My mechanic said he used to throw belts on his drag car at high rpm and a guy at the track told him to run the green Kevlar belts from napa. He did that and hasn't thrown a belt since. They are used a lot on farm equipment and are stronger he said. He told me to go get a green belt and try it. Have you guys ever heard of doing that?

 

[565bbchevy]

I would check your pulley alignment very carefully, that is typically the cause of thrown v-belts, along with inproper tension.
I use Gates v-belts that are black and I spin my BBC to 7400 RPM and have no issues throwing belts

 

[mobileaudio25]

I would check your pulley alignment very carefully, that is typically the cause of thrown v-belts, along with inproper tension.
I use Gates v-belts that are black and I spin my BBC to 7400 RPM and have no issues throwing belts

Do the gates v belts not twist as easy as a standard parts store v belt? Is there a better way to examine the pulleys alignment rather than just with just the naked eye?

I noticed my water pump pulley has a slight awkward spin when I do it by hand, could the pulley itself be warped?

When it comes to tension to an extent the tighter the belt the better correct? Also run a smaller belt rather than a larger one

 

[L67ss]

Like a wobble?

 

[565bbchevy]

Are you running steel pulley's? If you see any pulleys with even a slight wobble it could easily through a belt at higher RPM and I would replace them first.

 

[565bbchevy]

Assuming this is a SBC and you are throwing the alternator/water pump belt can you see marks on the edge or sides of any of the pulleys that would be caused by the belt rolling off?

 

[Clone TIE Pilot]

Assuming this is a SBC and you are throwing the alternator/water pump belt can you see marks on the edge or sides of any of the pulleys that would be caused by the belt rolling off?

The HO 305s have a serp belt for the water pump and alternator.

 

[565bbchevy]

The HO 305s have a serp belt for the water pump and alternator.

Well, I am guessing he doesn't have an HO then if it is running hot after throwing a v-belt.
That should also solve the issue if he could get all the pulleys from an HO 305.

 

[olds307 and 403]

The US made Gates belts are well made but the new belts stretch a lot. I find they need tightened 3 or 4 times. Check your alignment, my car threw belts till I aligned the pulleys, they were out, I used a straight edge. Dayco makes a laser alignment tool and their US made belts are also decent.

 

[axisg]

Like mentioned above, look out for the flat belt from the later 80's SBC on things like the gbody, caprice and fbody. I don't recall the setup on any of the pickups but I could be wrong.
My 84 SS was a HO305 and had the vbelts so that's not much of a guide. IIRC I got a set from a late 80's SBC Grand Prix and another set for a friends car from a member on the site. In my case I put a nice dent in my hood when the Vbelt let go on my car for the last time. IIRC 85 was the changeover year. 86 and after SS would have the "flat" belt that runs crank, WP and alt. And they would still have a Vbelt for AC Compressor