Cometic C10086-HB-040-020 MLS Head and Base Gasket Kit 4.125" Bore

The Cometic C10086-HB-040-020 is a complete head and base gasket kit designed for Harley-Davidson Twin Cam engines with 4.125" big bore cylinders, commonly used in 107" and 117" displacement builds. This kit features Cometic's proven Multi-Layer Steel (MLS) technology for superior sealing performance in high-output motorcycle applications.

Kit Includes:

• Pair of MLS head gaskets with .040" compressed thickness and 4.125" bore
• Pair of MLS base gaskets with .020" thickness

MLS Construction Benefits:

• Three-layer design with stainless steel core and Viton-coated embossed outer layers
• Withstands extreme cylinder pressure and thermal cycling
• No re-torque required after installation
• Resists corrosion and maintains seal integrity over time
• Reduces bore distortion compared to traditional gaskets

Cometic MLS gaskets feature embossed outer layers coated with Viton, a fluoroelastomer material heat-resistant to 482°F. The multi-layer construction allows the gasket to rebound and conform to head and block surfaces while handling the shearing forces created in high-performance engine environments. Ideal for both street and performance applications on Twin Cam big bore builds.