GM LS1/LS6 Harmonic Damper - Non-SFI

The Professional Products GM LS1/LS6 Harmonic Damper – Non-SFI is a precision-engineered crankshaft component designed for high-performance LS-series engine builds. This internally balanced harmonic damper features a 7.5-inch outer diameter steel construction with black finish, engineered to absorb and dissipate the torsional vibrations inherent in aggressive engine operation. Built for engine builders and performance enthusiasts who demand reliability under sustained high RPM loads.

The damper's internal balance design integrates the counterweight directly into the assembly, reducing overall complexity while maintaining precise vibration control. This configuration is essential for LS-series engines subjected to forced induction, extended RPM ranges, or competition use where harmonic loading becomes critical. The 7.5-inch diameter provides optimal leverage for damping characteristics across the full rev range. Steel construction offers proven durability in both street and track environments, with black powdercoat finish providing baseline corrosion resistance for engine bay exposure.

This damper is engineered for LS1 and LS6 applications where OEM or mild-performance dampers show inadequate vibration management. Engine builders choosing non-SFI components for dedicated track vehicles, vintage restorations, or experimental builds will find this part suitable for internal-balance engine configurations. The non-SFI designation indicates it is not certified for vehicles requiring SFI sanctioning—verify local track or competition requirements before purchase. Compatible with LS-series engines using internal balance setups; confirm your specific engine variant requires internal rather than external balance configuration.