What is the purpose of counterweights in an engine?

Counterweights are crucial components in an engine, primarily designed to balance the off-center weights of crank throws and compensate for centrifugal force. As the engine operates, the crankshaft rotates and experiences forces due to its weight distribution and the motion of the pistons. Without proper balancing, these forces can cause vibrations and instability, which lead to wear and stress on engine components.

By incorporating counterweights, the engine achieves a more balanced operation, which allows it to run smoothly. This balance minimizes the effects of vibration and enhances overall engine performance and longevity. The use of counterweights is particularly important in high-speed applications where centrifugal forces can become significantly more pronounced, making this balancing act essential for maintaining engine integrity and reliability.