Water pump pulley diameter

[roccodart440]

A recent thread made me question if I have the correct water pump pulley diameter.

There seems to be two sizes available for the big blocks,
6.750" or 5.938"

Which would be the desired pulley diameter?

 

[Dana67Dart]

What is your crank pully dia.

Crank dia / Waterpump dia x 100 = %


JUST NUMBERS FOR EXAMPLE
(6.5 / 6) x 100 = 108% or 8 percent overdriven

(6.5 / 6.75) x 100 = 96.3 or 3.7 percent underdriven


That will give you a ratio of crank to Waterpump. One i suspect will be underdriven and one will be overdriven.

The waterpump you have will need to match the situation.

Can't say for BB but in SB there us a relation like ( and someone correct me if i have this backwards) AC and HD cooling were overdriven BUT the waterpump had fewer vanes. Standard cooling was underdriven but had more vanes.

 

[famous bob]

What is your crank pully dia.

Crank dia / Waterpump dia x 100 = %


JUST NUMBERS FOR EXAMPLE
(6.5 / 6) x 100 = 108% or 8 percent overdriven

(6.5 / 6.75) x 100 = 96.3 or 3.7 percent underdriven


That will give you a ratio of crank to Waterpump. One i suspect will be underdriven and one will be overdriven.

The waterpump you have will need to match the situation.

Can't say for BB but in SB there us a relation like ( and someone correct me if i have this backwards) AC and HD cooling were overdriven BUT the waterpump had fewer vanes. Standard cooling was underdriven but had more vanes.

more pulley sizes than those !

 

[Brooks James]

Subscribed, i have a non ac pump pulley on my 360, but i have a seperate ac pulley that is about 2/3 the diameter of the non ac one, i also have a hi vol pump and if i have any cooling problems i will but on the ac pulley. It is my understanding that the smaller ac pulley will druve the rpm's up by
30%

 

[roccodart440]

more pulley sizes than those !

Those are the only two sizes listed on summit

 

[oldkimmer]

There is about 10 different sizes. from 6 1/4 to 7 1/4. Same with the crank pulleys, a few different sizes. Kim

 

[roccodart440]

There is about 10 different sizes. from 6 1/4 to 7 1/4. Same with the crank pulleys, a few different sizes. Kim

I plan to take a crank pulley diameter and water pump diameter and post them in this thread to get some accurate recommendations for my water pump pulley diameter.