FLIPPING MY ALTERNATOR BELT

[Mike Gaines]

After Installing my Meziere Electric Water Pump (and removing my belt driven water pump) I, of course, had to install a shorter belt because the new belt was just running from the crank pulley to the alternator pulley, NOT also running over the water pump (3rd pulley) pulley anymore.
Never had any problems whatsover flipping my belt when it was driving both the alternator AND the water pump....but now...with the belt just coming off the crank pulley and driving the alternator the belt flips off on every run down the drag strip.

I DO NOT have a "deep groove" pulley on my alternator and I guess this would be the problem as the belt does not really "seat" down in the pulley groove deep enuf....but I never flipped the belt before and I am running exactly the same size belt (just shorter)...any suggestions..and where would I get a "deep groove" alternator pulley, if that is what I need.

 

[5.7 hemi]

Could you switch to a serpentine belt with matching pulley's?

 

[dual fours]

Just a suggestion, the older belt could have been worn thinner then the new belt. Are the two pulleys lined up right? Any chance you could go to a thinner 3L belt?
And there is a spray on belt dressing to make the belts stop slipping, this does work.

 

[Yatzee]

After Installing my Meziere Electric Water Pump (and removing my belt driven water pump) I, of course, had to install a shorter belt because the new belt was just running from the crank pulley to the alternator pulley, NOT also running over the water pump (3rd pulley) pulley anymore.
Never had any problems whatsover flipping my belt when it was driving both the alternator AND the water pump....but now...with the belt just coming off the crank pulley and driving the alternator the belt flips off on every run down the drag strip.

I DO NOT have a "deep groove" pulley on my alternator and I guess this would be the problem as the belt does not really "seat" down in the pulley groove deep enuf....but I never flipped the belt before and I am running exactly the same size belt (just shorter)...any suggestions..and where would I get a "deep groove" alternator pulley, if that is what I need.

As a millwright for 30 years I have learned that there are only two reasons why v-belts flip. One is alignment of the pulleys and the other is tension. In your case shortening the belt has made both of utter importance. The reason a belt flips is because there is more friction on one side of the belt face than the other. This unbalanced friction causes the belt to ride up on one side of the pulley and flip over. If the top face of the belt is not at least flush with the top edge of the pulley you will compound this problem as there is less pulley face to maintain the belt's position as it rides in the pulley. Keep these things in mind:
1- The drive and driven pulleys are the same groove size and face angles
2- The belt is the right profile for the pulley grooves
3- The alignment of the pulleys is exact in both planes - lateral and verticle
4- The shorter the belt, the less deflection when tensioning - there are set deflection values for all distances between pulley centers and belt sizes used.
Over and under tensioned belts react differently- one climbs, the other slips.
5- Pulleys that are not true radially or laterally will never track true
6- Every certified pulley has a safe rotational speed before self destruction
7- Never buy a cheap pulley (China discount) that is not engineered "certified"
8- Ensure there is no misalignment between driven and drive pulleys induced when under load or at high rpm's

 

[dvw]

We've also learned once an old belt has "flipped" it will continue to flip.I agree with all above and a new belt. A narrower belt will allow it to set lower in the pulley has helped us (with proper pulley alignment).
Doug

 

[66Satellite47]

Correct alignment, VERY carefully checked & probably a narrower belt. Agreed that once a belt has flipped, it's way more likely to keep doing it. A shorter belt only driving the alt doesn't have to be as large cross section, so a narrower belt with the correct angle will work well and be deeper in the groove.

 

[Darthomas]

Seems counter-intuitive, but a larger cross section belt that seats in the pulley completely, yet rides above the level of the pulley might solve the problem.
I had to do this with an aftermarket AC compressor where only one belt could be installed, but was unable to take the load when the system was charged correctly.
It would flip or just snap the belt on a hot day. After buying the next larger cross-section belt, it never happened again.
The belt top was about 1/8 of an inch above the pulleys, but did fully sit down in the groove. And I had fully aligned the AC compressor on its bracket, hoping to make a difference. Nothing made a change until I did this.
I COULD leave the system undercharged, but then the evap would always frost over, so I did not consider that a reasonable solution.

 

[66Satellite47]

Mike, By the way, do you run a cut out switch with the alt? Seems to me that may help. Just a thought.

 

[383man]

We've also learned once an old belt has "flipped" it will continue to flip.I agree with all above and a new belt. A narrower belt will allow it to set lower in the pulley has helped us (with proper pulley alignment).
Doug

Same thing I found. And thats once a V-belt flips it keeps doing it even when the problem was fixed we still had to put a new belt on it. At least its always been like that for me. Ron

 

[dvw]

Seems counter-intuitive, but a larger cross section belt that seats in the pulley completely, yet rides above the level of the pulley might solve the problem.
I had to do this with an aftermarket AC compressor where only one belt could be installed, but was unable to take the load when the system was charged correctly.
It would flip or just snap the belt on a hot day. After buying the next larger cross-section belt, it never happened again.
The belt top was about 1/8 of an inch above the pulleys, but did fully sit down in the groove. And I had fully aligned the AC compressor on its bracket, hoping to make a difference. Nothing made a change until I did this.
I COULD leave the system undercharged, but then the evap would always frost over, so I did not consider that a reasonable solution.

If we run the thick belt that sticks up over the pulley on my sons car it pitches it. The thin belt that rides down in the pulleys stays on with out issue.
Doug

 

[Darthomas]

If we run the thick belt that sticks up over the pulley on my sons car it pitches it. The thin belt that rides down in the pulleys stays on with out issue.
Doug

That's the great and wonderful mystery of life, what works in one situation doesn't work in another.
Also the reason we share experiences here, so we can learn from others.

 

[Yatzee]

After Installing my Meziere Electric Water Pump (and removing my belt driven water pump) I, of course, had to install a shorter belt because the new belt was just running from the crank pulley to the alternator pulley, NOT also running over the water pump (3rd pulley) pulley anymore.
Never had any problems whatsover flipping my belt when it was driving both the alternator AND the water pump....but now...with the belt just coming off the crank pulley and driving the alternator the belt flips off on every run down the drag strip.

I DO NOT have a "deep groove" pulley on my alternator and I guess this would be the problem as the belt does not really "seat" down in the pulley groove deep enuf....but I never flipped the belt before and I am running exactly the same size belt (just shorter)...any suggestions..and where would I get a "deep groove" alternator pulley, if that is what I need.

A larger cross-sectioned belt will ride high but have a tendancy to wear down into the pulley over time leaving ridges at the top of the belt. Once this occurs, the belt cannot pull down deeper into the pulley so side contact of the belt is compromised. Some supply houses substitute or tell you different belts are actually the same in cross-sectional measurements but this is not true. there even exist metric belts that are substituted for A or B belts but the angle of the faces can be slightly different reducing the contact area of the belt in the pulley or ultimately causing severe wear and the belt snaps or turns over. Always use the belt specified by the pulley manufacturer(s) and make sure both pulleys are of the same spec's for the belt intended.

 

[Mike Gaines]

Has anyone purchased a genuine DEEP GROOVE alternator pulley, if there even is one ?

 

[5.7 hemi]

Chevy has some from the factory. CVF may have some.