Cometic C9817 HD Big Twin Base Gasket Set 84-99 - 2 Pack .020" Copper

The Cometic C9817 is a premium heavy-duty base gasket set designed for Harley-Davidson Big Twin engines from 1984 to 1999. This 2-pack includes copper head gaskets with a .020" (0.020 inch) thickness, ideal for stock bore applications or mild performance builds.

Key Features:

• Premium copper construction for superior heat dissipation and sealing
• .020" thickness allows for precise compression ratio tuning
• Heavy-duty design withstands extreme cylinder pressures
• Direct replacement for stock base gaskets on Evolution Big Twin engines
• Set includes 2 gaskets for complete cylinder installation
• Compatible with 1984-1999 Harley-Davidson Big Twin applications

Cometic gaskets are manufactured using advanced materials and precision manufacturing processes to ensure consistent thickness, superior sealing, and long-lasting durability. Copper base gaskets are particularly effective in high-performance applications where heat management is critical, as copper conducts heat away from the combustion chamber more efficiently than traditional composite materials.