Fan Belt issue

[Cobra #3170]

I am having an on going problem with the fan belt on my FE and wondering if anybody has had something similar and perhaps solved the problem.
The front of my engine has three separate belt drives, the first is a cogged belt for the Dailydry sump pump, next is a Dayco top cog multi- ply V belt driving the alternator and water pump. The last belt is a 6 rib micro vbelt driving the power steering pump. I have a Nippondenso 65 amp alternator out of a Camry that is mounted on the right hand side of the engine similar to original stock location. The lower pivot is a 5/8" bolt and the upper mount picks up two places on the water pump so it is very solid. I spent considerable time aligning the pulleys and believe they are very close to perfect although they may not be under load. The alternator has a standard depth v pulley that does not allow the belt to drop down in the v, it uses a tapered metric shaft. I added a bolt over the top of the belt about half way along the distance to the water pump to try and prevent any harmonic belt oscillation which helped a little.
The problem: Any time the engine gets over about 7600 - 7700 rpm it tosses the belt
it is so bad they I carry 5 extra belts with me because I never know when one will come off, sometimes they last for several weeks of autoxing today we lost two belts 10 minutes apart. Packaging a serpentine drive would be a nightmare because the alternator pulley is really close to the upper suspension cross member. I am thinking a deep groove alternator pulley might help but finding one for this alternator would be tough. Current belt is a 15445 which is relatively short. Any ideas?

[LMH]

Does it break the belt or just through it off?
A really dumb question but is the 15445 belt an automotive belt?
Larry

[Gaz64]

I see three choices.

Turn the rpms down.

Fit a smaller crank pulley.

Fit a full serpentine belt system.


7700, the alternator is doing 10000-15000? The belt is doing about 1/3 engine speed?

[wrench87]

It could be possible that the Camry Alternator pulley uses a different belt more then likely a metric belt that has a different depth , if the belt sits to high in the groove it will come off at higher rpms.

[jhirasak]

Is it possible to machine the existing Camry alternator pulley with a deeper vee to reduce the tendency for belt tossing?

[Cobra #3170]

Originally Posted by LMH

Does it break the belt or just through it off?
A really dumb question but is the 15445 belt an automotive belt?
Larry

A Dayco 1445 is a racing automotive belt, the last belt from yesterday actually rolled over and is upside down and still on the pulleys. I was able to drive it in the trailer and it is still functioning. About 70% of the time it throws the belt it does break it sometimes if the alternator is pulling a big load. Peak power is 7600 so I really don't want to reduce RPM. I was wrong about alternator output it is 60 amps.
I found some circle track sources that make a deep groove pulley for that alternator that is larger in diameter so that might reduce the high rpm load enough to keep it together. The electrical load is high because there are two fuel pumps, electric water pump, MSD 6al, fuel injection system, and electric fan that I have on sometimes.
A serpentine would be nice but would require a major redesign of the front accessory drive that I can't take on now. Trying to get the car handling on street tires continues to be a major challenge that is taking all my time.
I am pulling the Torsen T2R Diff today and trying an Eaton Trac-loc. I was getting a horrendous vibration on corners yesterday and I think it was the Torsen beginning to give up. Thanks for the suggestions keep them coming!

[LMH]

I think the deep groove pulley for the alt is a good idea. Might help.
Larry

[Morris]

Bruce

Try this .....slow the alternator down....we use a

https://www.cvproducts.com/Uploads/2...er_Catalog.pdf

Denso Alternators

It worked for us...

[Morris]

3" pulley ...7/16" belt.....Napa belt......7500 rpm

[Cobra #3170]

Originally Posted by Morris

3" pulley ...7/16" belt.....Napa belt......7500 rpm

Thank Morris,

I use the 8102 alternator now, that 3" pulley looks good and has a deeper groove than what I have now. I will give it a try I already pulled the revs back from 8200 because that was a sure belt loss every time. Turning it slower with the 3" pulley will certainly reduce belt stress and the larger deep groove pulley will track better too. Napa belt will be cheaper than what I run now, not so sure that top cog is a good idea either seems to twist easier and then go upside down.

[DanEC]

Dang - 8200 rpm on an FE.

[Morris]

Bruce

Here's the belt # we use.....




Hope it helps out.....

Morris

[Morris]

"I am pulling the Torsen T2R Diff today and trying an Eaton Trac-loc. I was getting a horrendous vibration on corners yesterday and I think it was the Torsen beginning to give up. Thanks for the suggestions keep them coming!"....

Bruce

Have you tried a Quaiffe diff yet ??

Morris.

[timothale]

Bruce. I changed engines in my t bucket, At my age I don't need all that horse power, the old FE engine had a rare Isky cam kit that used 1.5 rockers and I would rev it and whip the fan belt and they would end up side down. after a couple changes they would still turn so I left them on and they would eventually end up round like a rope. The "round " belts would still run the water pump and keep thinges charged. But you have a lot more at stake in your engines.

[Morris]

Hey Bruce

How's your belt issue coming.....did you come up with a fix ???

[Cobra #3170]

Originally Posted by Morris

Hey Bruce

How's your belt issue coming.....did you come up with a fix ???

Hi Morris,

Thanks for asking will find out this weekend, belt speed was 242 feet per second which is enough to make it grow and come off the pulleys. I installed a smaller crank pulley by using the starter to unscrew the allen head bolt holding it on. I am hoping the lower belt speed will work. I think someone on CC perhaps you, suggested this earlier but I did not think I could get the pulley off with out raising the engine. I was desperate enough to try the starter trick (old one).

I had new floating front brake rotors and hats made (at great expense I might add) and asked for .012" of lateral float. The company that built them thought that was too much and gave me .007. Although better, I still have brake knock back and will have to machine .005 off rotor pads to really fix the problem.
I will try the brakes this weekend, hopefully they won't go to the floor like the fixed rotors did.

We are trying three different tire combinations and a new splitter I fabricated that bolts on to existing hardware without effecting the stock body this week end too.

Will share results next week.