Speedmaster PCE291.1012 SFI 18.1 Harmonic Balancer 6.75" External Balanced for Chevy 383 400

The Speedmaster PCE291.1012 is a race-quality harmonic damper designed for externally balanced Chevy 383 and 400 cubic inch small block engines. This SFI 18.1 certified balancer features a 6.75-inch outer diameter and provides critical vibration damping to protect your crankshaft and bearings while maximizing engine performance and longevity.

Key Features:

• Manufactured from forged K1045 low carbon steel for exceptional strength and durability
• Tuned elastomer layer bonded between hub and inertia ring using advanced adhesive technology
• External balance configuration with built-in weight offset for Chevy 383/400 applications
• SFI 18.1 certified for competition use—tested to withstand 15 tons of press force without separation
• Clear white timing marks on painted black background for easy degree reading
• Steel inertia ring absorbs torsional vibration across all RPM ranges

This harmonic damper uses a superior bonding process that adheres the elastomer to both the inner diameter of the inertia ring and outer diameter of the hub, creating a significantly stronger bond than conventional designs. The steel inertia ring rotates harmonically with the engine, absorbing torsional vibrations from the rotating assembly at any frequency. By reducing harmful crankshaft flex and bearing stress, this damper allows your engine to produce more power and torque while extending component life.

Important: This is an externally balanced damper. External balance dampers feature a visible weight or casting offset on the backside (crankshaft side) of the unit. Verify your engine's balance type before ordering—external balance dampers are NOT interchangeable with internal (neutral) balance applications.