HI John
The standard Pside-Kick kit model PK1A uses a CSV1A Cycle Stop Valve. This valve will work up to 25 GPM, but it comes standard with a 1 GPM bypass which is adequate to cool 2HP and smaller motors. A 3HP needs about 3 GPM minimum to stay cool. We can easily make a CSV1A with a 3 GPM bypass, but that means it fills the tank at 3 GPM instead of 1 GPM, so you need a little larger tank. Also, while the CSV1A will work to 25 GPM, that is the max so it has friction loss of 25 PSI at 25 GPM.
If you never use as much as 25 GPM, you would never see this friction loss. But if you actually use 25 GPM, the CSV2W only has 15 PSI loss and comes with a standard 5 GPM minimum. We can make you a CSV1A with a 3 GPM minimum or you can use a CSV2W, but either way you need a 20 gallon size tank that holds about 5 gallons of water. So to answer your question the PK1A kit is just a little small for a 3HP.
