[jjfish]

Hey. I went with a two groove alternator. I also have ac and power steering.
how would you route the belts. I have a two groove water pump pulley and a three grove crank pulley.
69 351w
Thanks

 

[jjfish]

I should probably add, it’s a 130amp 3 wire alt

 

[jjfish]

I’ve been thinking a 4 groove crank pulley but haven’t found any.

 

[MustangGrande302]

I have a 302 v8 out of an 80s ford in my 70 Mustang. I can show you how I route my pulleys once I get a few pictures. Keep in mind you may have to reroute it a different way since you have a different engine and other items. I would look at what other people have to say as well.

 

[MustangGrande302]

Here's how I have my pulleys arranged. I do not run a 2 groove water pump like you do, but I run a 1 groove. I have power steering, an alternator, and a/c like you do. I run a 3 groove crankshaft pulley. The closest to the block is for my water pump & power steering.

Next up is the groove in front of it which is for my alternator.

3rd groove in the front is for my a/c. Belt needs to be replaced so I have it off right now. I run a tensioner pulley for it as well.

That's my belt setup. Keep in mind, I run the stock alternator and stock York compressor. Power steering is a different story since it isn't stock. I know your water pump pulley is different, but maybe you can change it or find another way to hook it up with another person's suggestion. Hope this helps!

 

[66coupe289]

That might be a tough nut to do with V-belts. I have dual V belts on the alternator to keep from squealing, but not other accessories. CVF Racing was good for my application. No 4 belt crank pulley for you. You may have to consider serpentine.

 

[MustangGrande302]

One more question I might add, can you send pictures of how your accessories and pulley are lined up? That can give people a clearer view of how they suggest routing your belts.

 

[66coupe289]

One more question I might add, can you send pictures of how your accessories and pulley are lined up? That can give people a clearer view of how they suggest routing your belts.

Lining up is one thing, quantity is another. For what he is doing he needs 2 for the alternator, one for AC and one for PS. All need to run off the crank, thus a 4 belt crank pulley needed. The two belt alternator is really the odd ball thing here.

 

[66coupe289]

Potentially a long belt could be used to go from crank to alternator to AC (outlined in red), but engagement on crank pulley would be limited as it would only engage 1/4 the circumference of the pulley or so and thus it might be subject to slip, especially when AC engaged. Given the price of a belt, it may be worth a try. It would allow a 3 groove crank pulley. Equal belt speed for the alternator should be okay as long as the two grooves on the crank pulley are the same diameter. Any time I change my double alternator belts I change BOTH and both MUST be same brand. Belt profile is critical for them to ride at the same depth (diameter) in the pulleys, thus keeping the same speed. Would the shorter alternator only belt wear quicker than the the long AC belt, or visa versa? Who knows, as both are loaded slightly differently and the shorter belt will experience more overall rotations than the longer belt.

 

[MustangGrande302]

Potentially a long belt could be used to go from crank to alternator to AC, but engagement on crank pulley would be limited as it would only engage 1/4 the circumference of the pulley or so and thus it might be subject to slip, especially when AC engaged. Given the price of a belt, it may be worth a try. It would allow a 3 groove crank pulley. Equal belt speed for the alternator should be okay as long as the two grooves on the crank pulley are the same diameter.

View attachment 847922

I believe the picture you showed has the belt layed out differently. I see the a/c compressor going to the crankshaft pulley and to the water pump. The belt near the alternator appears to go to the water pump and down to the crankshaft pulley and back.

 

[66coupe289]

I believe the picture you showed has the belt layed out differently. I see the a/c compressor going to the crankshaft pulley and to the water pump. The belt near the alternator appears to go to the water pump and down to the crankshaft pulley and back.

Absolutely the picture shows a different routing. The "potential" ALTERNATIVE routing I outlined in red is NOT the usual routing, but it extends the AC belt to also pick up the alternator. The picture as taken only has 1 belt going to the alternator. The OP needs two to avoid belt squeal with a high output 3g alternator. It is a compromise that may or may not work long term due to differential belt wear. Furthermore, it does not have as much belt in contact with the crank pulley thus it could slip. It's probably a $20-25 risk to try it based on the cost of a long belt. The OP could just jump into a $720 CVF or March serpentine set of pulleys and be done. By nature I am cheap and I like to experiment. $25 gamble or $700+ sure thing? We all make choices.