Engine horsepower

An internal combustion engine can, temporarily, develop at any speed a maximum usable horsepower; also, can temporarily, run at much higher speeds than economically feasible with regard to dependability and repairs for industrial or drilling service. Also there are accepted procedures for measuring the horsepower for an engine that is not pulling its own water pump, fan, or take off bearing. It is therefore customary for the manufacturer to specify a recommended maximum speed for a given service and a recommended conservative maximum temporary horsepower for intermittent loads, such as hoisting, and a still more conservative maximum continuous horsepower for steady loads, such as driving a pump. In most instances these properly involve also the allowance having been made for water pump, radiator fan, power take off bearing, and generator.