440 with A/C: 3 or 4 groove crank pulley ?

[Kern Dog]

Most pictures I see of big blocks with A/C show them with a 4 groove crank pulley. Two belts drive the A/C pump and alternator, 1 belt drives the water pump and one belt drives the P/S.
A few times, I have seen a 3 belt setup. 2 belts still run the A/C pump and alternator but then I see a single belt that drives both the water pump and P/S. The 3 groove setup seems to look cleaner and simpler.
Does anyone know the year and model of vehicle that the 3 belt arrangement came on?

[cdr]

I have 4 belts, I recommend using the smaller AC water pump pulley.

[Kern Dog]

Smaller, to speed up the flow of coolant. Smart.   

[cdr]

Smaller, to speed up the flow of coolant. Smart.   

It also turns the fan blade faster.

[John_Kunkel]

Keep in mind that, when the factory went to the smaller WP pulley, they also used the 6-vane pump instead of the standard 8-vane. They believed that overdriving the 8-vane would cause cavitation.

[A383Wing]

Keep in mind that, when the factory went to the smaller WP pulley, they also used the 6-vane pump instead of the standard 8-vane. They believed that overdriving the 8-vane would cause cavitation.

yes, you must use the smaller 6 vane pump when you use the smaller water pump pulley....

I found this out long ago....car was fine when cruising around town, but the minute I got on the freeway, the temp climbed up considerably

[Kern Dog]

Since I have a couple boxes of pulleys from several parted out cars, I decided to mock up some parts on a spare 440. I found that a 3 groove setup will work as I had hoped. There will be 2 belts for the A/C and alternator and one belt to drive the water pump and P/S. I have a WP pulley that will work but it is a 2 groove. I would prefer to use a single groove WP pulley but I don't know where I can find one 5 1/4" in diameter and 1 1/2" deep. I'll probably use this 2 groove until I find a single groove someday.

[A383Wing]

If you use the 2 groove water pump pulley, you need to make sure that the 3 groove crank pulley belt grooves are the same diameter and width, otherwise you will get belt squeal from the belts fighting each other

Did that make sense?

[Kern Dog]

Yes it did. I have a stash of different belts here to use for mocking stuff up. The crank pulley grooves are deeper than the water pump pulley...not sure if that matters.

[A383Wing]

as long as the grooves are the same diameter, it will be fine....