I can see it producing 4 HP at a seriously sharp peak in the power wave, and for such an instantainious amount of time, it just barely lasts long enough to be considered HP.
Actual, usable HP would most likely max out at a continuous load of like 1/3 or possibly 1/2 HP, if it's being pushed enough and someone sprays the overload with a fire extinguisher. Any more than that would for sure lock the rotor or trip the overload [W/O fire extinguisher's CO2 applied [Linked Image] ].

I would like to see someone try to run a 4 horse pump from one of those motors! Boy, they would be mad! From the physical size, it looks like a 1/4 HP squirrel cage motor.
At around 40 PSI, the motor trips it's OL!

Scott SET

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!