As to how many HP it takes to turn a HV pump with a HP spring in it bear in mind you can spin the intermediate shaft during priming with cold oil using a Dewalt hand drill. If it took any appreciable power to do so you would break your wrist which obviously doesn't happen. How many horsepower can you hang onto with your hand? Perhaps 1/50th The actual power used is measured in the very low fractional horsepower range.
