Pulleys - Crank, Underdrive

Crank pulleys and underdrive pulleys play a critical role in engine performance by managing how power is transferred from the crankshaft to auxiliary systems like the alternator, power steering pump, and air conditioning compressor. A crank pulley, also known as a crankshaft pulley, is mounted at the end of the crankshaft and drives these components through a system of belts. Over time, or in performance-focused builds, replacing the factory pulley with an upgraded version can lead to measurable improvements in efficiency and responsiveness.

Underdrive pulleys are specifically designed to rotate accessories at a slower speed than stock configurations. This reduction in rotational speed lowers the parasitic drag these systems place on the engine, freeing up horsepower for better acceleration and throttle response. Underdrive pulleys are typically made from lightweight materials like billet aluminum, which also helps reduce rotational mass.

Choosing the right crankshaft pulley or underdrive pulley requires attention to compatibility, material construction, and balance. Many vehicles may require a specific type of crank pulley tool depending on engine layout and pulley design.

This collection includes a variety of pulleys and cranks suited for different applications, from daily driving to motorsport. The right pulley setup not only supports smoother engine operation but also contributes to longer accessory life by reducing unnecessary strain. For anyone upgrading their engine system or maintaining performance vehicles, understanding the function and benefits of crankshaft and underdrive pulleys is essential.