4in V-Belt Crank Pulley

The MOROSO 4in V-Belt Crank Pulley (MPN 23523) is a precision-engineered component designed for engine builders, street rod enthusiasts, and performance mechanics seeking improved belt drive efficiency and reduced accessory wear. This compact pulley addresses a critical weak point in traditional serpentine systems: inadequate load distribution across the crank interface.

At 4 inches in diameter, this MOROSO pulley offers a mechanical advantage that optimizes belt tension and reduces slippage during acceleration and sustained high-RPM operation. The V-belt groove profile is precision-machined to OEM tolerances, ensuring consistent contact with standard serpentine belts and minimizing vibration transfer to the engine block. The lightweight construction keeps rotating mass minimal—critical for fuel efficiency and engine responsiveness.

Mechanics upgrading carbureted small-block engines or restomod builds will find this pulley beneficial for reliable accessory drive operation, particularly under high RPM or heavy parasitic load conditions. MOROSO's reputation for manufacturing accuracy means this pulley maintains concentricity and balance from the factory, eliminating the need for secondary balancing operations.