SFI Test Lab! PRO/RACE Features: • “ALL STEEL” construction • Exceeds SFI Spec. 18.1 - Spin tested to 18,000RPM • Specially formulated bonded
elastomer • 100% CNC machined. • Billet steel inertial ring and hub • Splined inertia ring and hub • 60° of engraved timing marks (40° on SB Ford models) • Easily installed - Instructions included
Bonding on “Race” models only. The PRO/RACE Damper The PRO/RACE “ALL STEEL” Harmonic Dampers are designed and manufactured for racing and high performance street applications and are available for a wide range of engines. The PRO/RACE Damper is a direct replacement for the cast iron stock damper which is no longer permitted by most racing sanctioning bodies due to the danger of fracture and high speed disintegration or separation of the inertia ring from the hub. This problem is eliminated with a PRO/RACE Damper. The PRO/RACE “ALL STEEL” Harmonic Damper is also a must for all belt driven supercharger applications due to the additional torque loads on the damper hub and keyway which results in failure in nearly 100% of all blower installations with a stock damper. PRO/RACE now offers specific models for supercharged small block (#74265) and big block Chevy (#74267) engines. These special dampers include dual keyways and also feature six tapped holes to accept most blower pulleys. “RACE” vs “STREET” ALL STEEL Dampers PRO/RACE offers two styles of dampers for small and big block Chevys; a Race model and a Street model. The difference is that on the Race model the elastomer is bonded to the steel hub and ring. This bonding is particularly valuable on applications where sustained high speed is present such as marine or circle track applications. The Street models are suitable for moderate performance applications on engines making approximately 350 to 400 hp. The special splines (see cutaway photo) enhance the bonding between the elastomer and the inner hub and outer ring which helps prevent any outer ring radial movement, a common problem on OEM stock factory dampers. If you would like to use a Street style damper on a 400 small block simply combine our #64262 Street small block damper with our #65266 Counterweight and you will have the proper combination for that engine. Cutaway shows internal splines which provide for twice the contact area, eliminating any possible movement of the outer ring. External diameter of the inner hub is splined as is the inner diameter of the outer ring. Elastomer is vulcanized to the splined areas on Race units. This forms a very positive bond between the elastomer and the steel with twice the contact. Note splines on hub and ring.
