Cometic C9822 Copper Base Gasket 3-13/16" Bore .005" Harley Big Twin 2-Pack

The Cometic C9822 copper cylinder base gaskets are precision-engineered sealing solutions designed for Harley-Davidson Big Twin engines from 1984 and newer. This 2-pack features ultra-thin .005" (0.005 inch) solid copper construction that provides exceptional sealing performance and heat transfer characteristics ideal for high-performance engine builds.

Key Features:

• 3-13/16 inch bore diameter for proper cylinder fitment
• Ultra-thin .005" thickness allows precise deck height adjustment
• Solid copper construction for superior heat dissipation and conformability
• Heavy-duty design handles extreme cylinder pressures
• Sold as a 2-pack for complete engine rebuild
• Manufactured in the USA with American materials

Copper base gaskets are preferred by performance engine builders because they allow fine-tuning of piston-to-head squish clearance by stacking multiple gaskets or combining different thicknesses. The soft copper material conforms to machined surfaces and maintains a reliable seal even under high compression and temperature cycling. Compatible with Big Twin Evolution and Twin Cam engines.