Cometic C9937 Twin Cam Cylinder Base Gasket 4.0" Bore .010" Pair

The Cometic C9937 is a high-performance cylinder base gasket designed specifically for Harley-Davidson Twin Cam engines with a 4.0-inch bore. Manufactured from embossed stainless steel and coated with Viton on both sides, this gasket provides exceptional sealing performance in demanding V-twin applications.

Key Features:

• 4.0-inch bore diameter for stock Twin Cam cylinders
• .010-inch (0.25mm) thickness for precise compression control
• Embossed stainless steel construction for durability
• Viton coating on both sides resists heat, fuel, and oil
• Sold as a pair for complete engine service
• Made in the USA with American-sourced materials

Cometic base gaskets are engineered to meet the demands of high-performance V-twin engines, offering superior sealing in harsh environments with varying load conditions and surface finishes. The Viton coating ensures the gasket will not creep, crack, or become brittle over time, providing long-term reliability for your Harley-Davidson engine rebuild or performance upgrade.