Net power: the effective power output by the engine’s power output shaft that is measured when engine is equipped with all the parts needed for actual operation conditions and is operated in the regulated rotating speed in the engine laboratory table. It indicates the amount and speed of the work done, i.e. the amount of work done in unit time. The conventional unit of power is horsepower, and one horsepower refers to work done by 75kg applied force that move one meter in one second. To be unified with international unit, it is converted into KW. 1 PS=0.7355 kW. 
 
Net torque: the average torque output by the engine’s power output shaft that is measured when engine is equipped with all the parts needed for actual operation conditions and is operated in the regulated rotating speed in the engine laboratory table. The conventional unit of the torque is unit (N.m). When the power remains the same, the torque is in inverse relation with the rotating speed of the engine. The faster the rotating speed is, the smaller the torque is, and vise versa. 
 
Here, v means linear speed, and in the engine, crankshaft linear speed= crankshaft angular speed(ω)×crankshaft radius (r), substitute into the above formula: Power(p)= force(F) ×radius(r) ×angular speed(ω); And force (F) ×radius(r)=torque 
We can conclude that: power（P）= torque ×angular speed ω, so the power of the engine can be calculated from the torque and rotating speed. 
The unit of angular speed is radian/second, and in radian system, πmeans 180°.