Fan Belts

[Bruceynz]

Hi Guys,

Ok as some of you may know I am setting up a 360 to go in my Cordoba. Chrysler used a double belt system on the Alternator, I have set my engine up with just the water pump, alternator and power steering pump. My question is this, things only line up so one belt can be used to drive the alternator, is it necessary to run 2 belts on the alternator?

Many Thanks
Bruce

 

[Bruceynz]

If I want to run 2 belts do I need a different bottom pulley with another groove on it that will line up with the alternator?

 

[80mirada]

You can get by on one belt, to run two you need a 3 or 4 groove crank pulley, and either an idler pulley pr grin a rib off the water pump

 

[Bruceynz]

I could probably steel all the parts off the 318 that is in my car to make it work, but 2 belts looks so much more tidy, were 2 belts used on the alternator as a safety thing eg one broken you still had one or was it because of the loading the alternator could put on the engine when charging hard?

Thanks
Bruce

 

[80mirada]

It was a load thing, mostly. It helped on cars that had high electrical loads, A/C, towing etc. The problem was belts slipping or jumping off under acceleration or when the A/C compressor came on. The early "high output" alternators also had a tendency to squeal belts on cold mornings.

I have an idler setup mocked up under the hood of my Mirada. It came off of an 80s D150 that had no A/C, it bolts right in place of the compressor. I prefer the later pulleys and alternator bracket, I have had fewer pulley alignment problems with them.

 

[Aspen500]

The double belt was mainly to run the A/C, and the alternator was the tensioner basically. You can run the single belt with a double alternator pulley. If it looks too weird, you can change the pulley to a single groove. You'll need a dedicated puller/installer to do it though.

As an added bonus, the kit also works on power steering pump pulleys.

 

[Bruceynz]

But the way I have mine setup in the photos should all work ok, have tensioner with the Alternator and to tension water pump I have tensioner on power steer pump.

 

[Aspen500]

That should work fine. As long as the pulleys line up, it's all good.

 

[Bruceynz]

My only issue is the alternator when you tension it up because the bolt has a tiny amount of play in it on the shaft allows the alternator to twist ever so much, you can see it when you look at it hard enough, its amazing what your eye can see, is this an issue? its not much and you probably wouldn't even see unless I pointed it out.

 

[Cordoba1]

My only issue is the alternator when you tension it up because the bolt has a tiny amount of play in it on the shaft allows the alternator to twist ever so much, you can see it when you look at it hard enough, its amazing what your eye can see, is this an issue? its not much and you probably wouldn't even see unless I pointed it out.

You should do your best to line up the pulleys as much as possible. If not, the bearings in the alternator will fail pretty quickly. Your alternator is like missing a little sleeve that goes on the lower mounting bolt. That sleeve takes out the play. My alternator didn't have one, either, and I lost the original. If you tighten the lower bolt, the one the alternator pivots on, it'll usually take care of that slack that allows the alternator to rotate as your tensioning your belts.

 

[Bruceynz]

Here is a photo of my setup, I can get a better one tonight after work, but are you talking about that split sleeve the big bolt goes through? If you look hard you can see that split center bushing the bolt goes through. See attached pic
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Is there suppose to be a split center busing at the front of the alt by the bolt head?
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more pics

 

[Buck Atwater]

Your issue is that you have an A/C water pump pulley, and a non A/C alternator bracket. The power steering belt is supposed to go on the outer lower pulley groove, and the alt/fan on the inner. The proper non A/C water pump pulley has a much larger offset than yours.

 

[Bruceynz]

Will it work ok how I have it set up?

 

[Buck Atwater]

Will it work ok how I have it set up?

Well with the way you have it now, I guess you would want your 2nd belt to go around the power steering pump, crank pulley and w/p pulley. But I don't think the power steering pulley will line up with the w/p pulley you have, but I could be wrong. I went through all this about 12 years ago when I changed my Mirada over to a 360 from a slant 6, I forget some of the details now though. I had pile of mismatched brakets and pulleys that didn't line up, and ended up getting a matched set from a non A/C car later.

 

[Bruceynz]

everything lines up, will take some photos, one thing to note is the crank pulley is 2 different sizes pulleys on it, look close at the crank pulley. Why is this?

 

[80mirada]

Different drive ratio. They altered pulley sizes for alternators and powersteering

 

[Bruceynz]

which one is which?

 

[80mirada]

The alternator drive is usually smaller than power steering when they are different sizes. If I remember correctly.

 

[aspen77rt]

Mr. B

Here's the belt routing from my car if it helps. The outside unused groove is for an air pump IIRC
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Here's the only one I have from Aspen's motor before I pulled it.