BHJ Harmonic Damper Introduction

BHJ Harmonic Dampers offer the most precise and advanced execution of the proven elastomer-style harmonic damper (also referred to as Torsional Vibration Damper, or Harmonic Balancer) design.

Most engine designers prefer elastomer-type dampers because of their durability, superior high-frequency damping qualities, and ability to dampen all types of vibrations: torsional, axial and radial. Other damper designs are limited to damping torsional vibrations only.

S.F.I. 18.1 approved dampers are available for most engines in two versions, all steel and aluminum hub/steel inertia ring "Combo" styles. Both types are typically much lighter than the O.E.M. units they replace and are lighter than many competitive aftermarket dampers.

All-steel dampers have been manufactured by BHJ longer than any other company in the industry. They have proven their merit in thousands of applications, including offshore boats, drag racing, super speedways, short track, road racing and off-road, as well as street-driven sports cars, hot rods and grocery getters.

Aluminum/steel "Combo" dampers are a result of BHJ's experience in the performance industry. The Combo damper design mates a lightweight aluminum hub with a steel inertia ring and is available for most internal-balance dampers. Established damper technology proves that the mass of the non-damping elements in any design actually amplifies harmonic vibrations. Therefore, elimination of non-damping mass greatly improves the effectiveness of any damper. In many instances this will allow the use of a smaller size damper. The lighter hub and smaller size provide for appreciably faster potential acceleration.

BHJ's E-Performance dampers are an economical, nodular iron alternative for use in high-performance street or racing applications where S.F.I. certification is not required. The E-Performance damper series is also very popular in racing classes where a "stock-appearing" (non-S.F.I.) damper is mandated by the sanctioning body. E-Performance dampers are lighter than their O.E.M. counterparts and equivalent in price.

Both S.F.I. and E-Performance harmonic dampers are custom designed to meet each specific application and all critical O.E.M. mounting dimensions are duplicated for accurate alignment of accessory drives. All harmonic dampers feature a T.D.C. mark and when necessary, are degreed from 0 to 50 degrees B.T.D.C. in 2-degree increments for accurate ignition timing. 90-degree marks are also included for easy valve adjustment.

Externally balanced dampers feature a machined-in-place counterweight that precisely matches the O.E.M. unit it replaces and are available in all-steel or nodular iron only. Internal or neutral-balance Dampers are zero-balanced before shipment.

Custom Design Programs for specialized engine applications, vintage restoration and crate engine programs are also available in nearly unlimited configurations, whether S.F.I. certification is necessary or otherwise. Programs are available for a wide variety of budgets and production quantities. BHJ's state-of-the-art damper design technology assures precise tuning for outstanding performance and long engine life in any operating environment.

Click here for our White Paper on harmonic damper purpose and operation.