Easily installed - Instructions included
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.
Exceeds SFI Specification #18.1
This specification is enforced by most racing sanctioning bodies to assure that the dampers conform to specified standards. While the SFI test is quite stringent and requires the damper to be spin tested at a speed of 12,000 rpm for a period of one hour, the PRO/RACE Damper has been tested at a speed of 18,000 rpm, substantially exceeding SFI requirements.
We offer one SB Chevy and two Ford dampers with aluminum hubs. Also our #73265 is "All Steel" with a lightened inertia ring which reduces the weight of the damper by nearly 3.5 pounds. See Application Chart for all weights.
Extremely High Quality Standards
PRO/RACE Dampers are manufactured to extremely high quality standards that are constantly monitored and checked at every step of the manufacturing process.
Our quality levels in bore tolerance and the finish of the machined surfaces, in particular the critical oil seal area, far exceed OE standards and those of competitive models. Sixty degrees (60°) of computer generated timing marks (40° on Ford units) are accurately laser engraved. PRO/RACE Harmonic Dampers also feature engraved timing marks at 0°, 90°, 180°, and 270° (except Ford models).
Once assembly of the damper is complete, the entire damper is highly polished and then treated with a clear protective coating providing an extremely attractive appearance. Our instruction sheets make installation a snap. Our Dampers are designed for a direct replacement of the stock damper which means all your accessory pulleys still line up without modification. The dampers will accept most crank trigger wheels.
Harmonic dampers are supplied in two styles; those for internally balanced engines and those for externally balanced engines. Externally balanced engines have a counterweight bolted into the hub of the damper. The advantage of having a removable counterweight in the hub eliminates the possibility of having the counterweight mass move from its position.
The PRO/RACE Damper for internally and externally balanced small block and big block Chevys and for small block Chryslers is identical except for the counterweight. This means, for example, if you have a PRO/RACE Damper for a 400 small block Chevy you can remove the counterweight and the damper will work perfectly for a 350 Chevy. Conversely, if you have a 350 Damper and want to use it on a 400 you can now purchase the proper PRO/RACE counterweight and bolt it into your 350 damper and it is now a 400 damper.
All Ford dampers are externally balanced with a counterweight. This counterweight can be removed for use on internally balanced engines.
NOTE: Bonding on "Race" models only.