Cometic C4239-040 MLS Cylinder Head Gasket Honda Bore - B18A1/B18B1 81.5mm

The Cometic C4239-040 is a high-performance Multi-Layer Steel (MLS) cylinder head gasket engineered specifically for Honda B18A1 and B18B1 engines. This precision gasket features an 81.5mm bore diameter and 0.040-inch (1.02mm) compressed thickness, providing optimal sealing for stock and performance applications.

Key Features:

• Multi-Layer Steel (MLS) construction for superior sealing and durability
• 0.040-inch compressed thickness for precise compression ratio tuning
• 81.5mm bore diameter designed for B18A1/B18B1 engine specifications
• Embossed stainless steel layers with elastomeric coating for exceptional conformability
• Handles high cylinder pressures and temperature fluctuations
• Ideal for naturally aspirated, turbocharged, and supercharged builds

Cometic MLS gaskets are constructed from multiple layers of stainless steel with a proprietary coating that provides excellent rebound characteristics and chemical resistance. The advanced design allows the gasket to maintain seal integrity under extreme conditions, making it the preferred choice for performance and racing applications. This gasket requires a proper surface finish (typically 50 RA or smoother) for optimal sealing performance.