Cometic C9551 Cylinder Base Gasket SLS .020" Harley Evolution Big Twin

The Cometic C9551 is a high-performance single-layer steel (SLS) cylinder base gasket engineered for Harley-Davidson Evolution Big Twin engines with standard bore cylinders. This precision-manufactured gasket features a .020 inch (0.51mm) compressed thickness and is designed to provide a reliable seal between the cylinder and crankcase.

Key Features:

• Single-layer steel construction for exceptional durability and heat resistance
• Compressed thickness of .020 inches for proper compression control
• Standard 3.5 inch bore size for stock Evolution Big Twin cylinders
• Sold as a pair for both cylinders
• Precision-cut design ensures consistent sealing performance
• Ideal for engine rebuilds, performance upgrades, and maintenance applications

Cometic gaskets are manufactured using advanced materials and processes to meet the demanding requirements of high-performance V-Twin engines. The single-layer steel design offers excellent torque retention and sealing capabilities while withstanding the extreme temperatures and pressures found in motorcycle engines.