Power

POWER is defined as the rate of doing WORK, or WORK per unit TIME. Sometimes it seems that people are confused about the relationship between POWER and TORQUE. For example, we have heard engine builders,camshaft consultants, and other technical experts ask customers:

"Do you want your engine to make HORSEPOWER or TORQUE?"

And the question is usually asked in a tone which strongly suggests that these experts believe power and torque are somehow mutually exclusive.

In fact, the opposite is true, and you should be clear on these facts:

1. POWER (the rate of doing WORK) is dependent on TORQUE and RPM.
2. TORQUE and RPM are the MEASURED quantities of engine output.
3. POWER is CALCULATED from torque and RPM, by the following equation:

HP = Torque x RPM ÷ 5252