rmriggin

I got a quick question about dual alternator pulley setup on an fb. What belts are needed and... Anyone have pics of install. Sorry if this has been asked before. Just point me in the right direction if this has been answered already. Thanks.

Jeff20B

iTrader: (13)

Do you already have the dual sheave pulley? If not, I recommend a 3L220 belt that just goes around the main and water pump pullies. It works much better than dual belts and costs less too.

Anyway, just get another alternator belt for your dual belt pulley, if you already have one. It's like a 15315 or similar number.

rmriggin

I already have the yoohoo helt setup, but I just ordered a dual alternator belt pulley in hopes of underdrive, and no more belt squeek. I have replaced the alternator belt very recently and it still sqeeks. Belt dressing help for a little while, but then it starts squeeking again.

cdrad51

If you have squeaking with a yohoo belt, alt belt must be too loose, IMHO.

Jeff20B

iTrader: (13)

Ah, underdrive. Then you might need a different length belt. The length of 315 I mentioned earlier is for stock diameter pullies. I've tried a 320, but as it stretches with age, it requires the alt to be raised very high. I've also tried a 300 on my MG Midget project where the alt must be as low as possible to keep from hitting the hood.

Do you have a clutch fan? Does it slip with a yoohoo? If so, perhaps the clutch is freezing up. I've gbot to tell you that even with dual belts, my dying clutch fan was still causing the waterpump pulley to slip. I swapped it for another one and the slippage went away, but one belt was always tigher than the other one. I dropped the dual belt setup in favor of a yoohoo belt and there have been no problems since. I've got one on my MG and another on my REPU. They both have stock diamter pullies though. Is your underdrive pulley just the alt only? Or the main drive pulley as well?

Metallic_rock

Go to the junkyard, find an 86-89 Dodge Caravan. Yank the alternator. It's a 75amp and it comes with the dual belt. It bolts right in with a minimum amount of shaving on the mounting bracket. (5 minutes of work)


That's what I did. The car had a massive stereo system. With everything on including the brights, the blinker didn't dim anything. (did before)

Jeff20B

iTrader: (13)

My MG's alt slips because the 300 belt is getting stretched with use. I tried to fit a 295 on it, but it was simply too short. I'm going to have to get a 295 and break it in on a belt stretching machine. I'm also going to purchase some Napa yoohoo belts and break them in on it too since they're too thick when new (they over-tension the main drive pulley until they break in). They're like a 15 in thickness when we want a 13.

Bass

What belts do you use with this set-up? And just out of curiosity, how many amps does my stock alternator put out? ('83)

Metallic_rock

use two stock alternator belts, and your stock setup is 25-30 amp, I believe. It's been a while. the 75 amp alt is great for someone that wants a big stereo. Otherwise, don't worry about it. You can also just yank the pulley off and put it on your stock alternator.

If you want to know the amp rating, it should be on the back of your alternator.

Jeff20B

iTrader: (13)

Stock 1st gen alts are 50 amps give or take a little.

lovintha7

Isn't swapping a 2nd gen alt almost as easy? Just change the pullies?

Metallic_rock

Yes, it's much easier, I just mentioned the Dodge Caravan alternator because it already had the dual pulley on it. You don't have to pay extra for it.

H4Inf

Hmm, putting a dual pulley on an alt which only has one - wouldn't that put extra pressure on the bearings and aid in wearing them out faster?

Metallic_rock

racing beat sells dual alternator pulleys to ensure that the water pump pulley doesn't squeak when you pull off everything else. It's a very common mod, and I've never heard of bearings going out because of it.