
Brake horsepower(bhp) is measured by taking a drum filled with a fluid and attaching that to an engine. The power required to turn the drum is the brake horsepower - as the drum is ‘braked’ by the fluid.
Apparently they can do it via an electronic system now.The maximum horsepower of an engine is determined by achieving a braking horsepower equal to the output of the engine.The unit, horsepower, was originated by James Watt (1736-1819), the...