The concept of idle torque can be best explained using an example of a motorcycle. A motorcycle that is not in motion or has no wind rushing by its engine has, effectively, no torque. In order for the bike to be propelled forward, the engine must apply a certain amount of torque to spin the rear wheel. This is known as idle torque and is typically measured in pound-inches of force. Depending upon the type of engine, and the amount of various components within the engine, the idle torque can vary greatly from bike to bike.
The main source of torque in any engine is the crankshaft. As the crankshaft applies the force through the chain and drive system, torque is created. The amount of torque created is determined by the performance specifications of each individual engine. This performance specification is determined by a combination of factors, including the horsepower of the engine, the number of cylinders, and the number of revolutions per minute (RPM) of the engines power stroke. Additionally, idle torque can also be affected by the weight of the vehicle in motion, the amount of compression within the engine, and the air-fuel mixture ratio.
In order to calculate idle torque correctly, it must be measured in pounds per inch. This is done by simply multiplying the number of rotations per minute (RPMs) by the inertia of the crankshaft and then subtracting the perceived spinning resistance from friction and surface contact. It is important to note that idle torque can vary greatly from engine to engine, especially when different types of materials are used within the engines construction.
To read an engines idle torque it is important to use a Rotor Pro apparatus such as a torque meter or dynamometer. This tool is designed specifically for measuring crankshaft rotations and the force associated with them. By taking the measured values at different RPMs, an accurate account of idle torque can be found.
The idle torque of an engine can ultimately be affected by its overall design, maintenance requirements, and a variety of other factors. It is important to know how to measure it, as it can potentially provide insight into the longevity and general performance of an engine in motion. Without being able to accurately measure out the engine’s idle torque, identifying potential problem spots and diagnosing the engine can become extremely difficult. In the end, understanding idle torque and its related concept is a necessary step toward becoming a successful and experienced engine mechanic.
