Whats up guys I have a 71 chevelle 396.. Just picked my car up from the shipping place casue i got it shipped from NY to hawaii... when my dad had it it was driving awsome and the car ran at about 190 degrees he said. no problems at all. Now the first time I i drive it home from picking it up I noticed it was running hot liek way hot then smoke everywhere and the lower radaitor hose blew off and also the belt from the water pump to the alternator. i Get a new belt and fill her back up and it does it again. 3rd time i pul it out of the parking lot and do a little burn out and the belt flies off but the water pump stayed on. Now today for more trouble shooting i put another belt on kinda that was kinda torn up (the first on i had that blew off that was in ok shape) and drive around base for 5 min and when i got back to the parking lot the belt was still on but out of wack and if i would off gave it soem gas it would of popped off. The motor has abotu 2000 miles on in so its not like its a piece or crap so. If anyone can help me out id appreate that very much.. If u need any more information let me know this is driving me nuts i get the car for 3 days and it broke down 3x on me...
Thanx a lot...
Danny OB

When i swapped my small block for a big block, i spent 4 years trying to keep the belts on. I tried everytnig, different brakets from different years, custom made brackets, special pulls, and i even machined my on pullys...they all sucked and i keep throwing off belts. After all that time and money i decided to buy a March serpentine belt system. I have never had a problem since and it looks WAY cool!! The set up is not cheap but worth it.

Try this link

http://www.jegs.com/webapp/wcs/stores/servlet/category_10001_10002_10223_-1_11067

I tried shimmin the pullys and i just could not get it aligned up so i just said the heck with it and got the march pullys and brackets kit... post up pics when i get it in..

Danny OB
71 chevelle ss
373 gears 12 bolt posi
460+ HP
396/402 Big block

I would check to see that the water pump, power steering and alternator turn freely. It is possible that a seized or very hard to turn accessory could cause a problem.

The other thing is just to make sure the pulleys are lined up reasonably straight.

Make sure all brackets are tight and holding everything in proper alignment.

Use proper width of belt for the pulleys.

Under normal operation you should not have a problem.

Under high rpm operation it is possible to have problems, but for sure not at normal street driving rpms.

The problem is when you go out and "kick it" the belt will come off the alt. The first thing you need to do is make sure you have the correct belt for your pulleys and or fab up a simple guide on the under side of your alternator pulley about a quarter of an inch away from the belt and mount it by using the bottom (long) alternator bolt.

Hmmmm.. I 'kicked it' for the first time with my new engine the other day after some fine tuning and guess what? The belt popped off!

Had a similar problem until I replaced the power steering pump bracket.Someone had installed a small block bracket on a big block engine.The big block bracket has an additional support hole that bolts to the block preventing the bracket and pump from moving foward.Belt now stays on-no problems even when mashing the throttle.Also found was a piece of pipe used as a spacer for the alternator along with a piece of threaded rod from a hardware store.There was too much slop between the two allowing the alternator to flex and throw the belt under hard acceleration or high rpm's.Now have the correct factory alternator bolt and spacer-no more throwing that belt either.70 ss clone 454/T400.

Good Luck

If the pullys line up and the accsesories are spinning freely and the belt is coming off then you have the wrong belt. if you have the correct belt then you must have the wrong pullys. Are they deep or shallow groved?
Are the belts tight enough? Try to push and pull on the alt, power steering and water pump one at a time to see if they move forward or back. put some muscle into it when you check.
Put them on fire it up open the hood rev it up and watch what happens. Be sure to stay clear of flying belts

Good advice above on checking the bearings of all items to see if one is seized or on its way.

If the inside of the belt ( the smaller width) touches the root of the pulley groove, it is the wrong one for that pulley. Check all the pulleys. A v-belt should only ride on the tapered sides of the pulley groove.

Use a straight edge along the crank pulley to see how far off the others are. Shim the alternator mounting points as needed.

At idle, view each pulley for any wobble or off-centre rotation. A small block crank pulley on a bigblock can do this if not installed properly.

HTH.