Big Twin

Cometic’s line of big twin gaskets are sold both as kits and on an individual basis.

Today's lightweight engines are producing more horsepower, higher cylinder pressure, clamp load and extreme temperatures. Our commitment is to provide innovative, quality gaskets while maximizing your engine’s power and performance. Cometic’s gaskets are proudly made in the USA with materials manufactured on American soil.

Gasket Terminology and Materials

MLS Gasket
MLS Gasket

MLS (Multi-Layer Steel) Head Gaskets

Provides maximum sealing performance for today’s high output engines and require no sealants. MLS gaskets are ideal for both aluminum heads to aluminum blocks and aluminum heads to cast iron blocks. They can withstand the shearing force created by the two materials. MLS gaskets have increased strength because they are comprised of multiple layers of stainless steel; which also creates the ability to rebound and resist corrosion. The outer layers are embossed and coated on both sides with Viton (a flouroelastomer rubber based material that is heat resistant to 250 C/ 482 F). Viton is designed to meet the demands of a variety of harsh sealing environments, load conditions, and surface finishes. The center or shim layer is uncoated stainless steel, which can be varied to accommodate multiple thickness requirements.


LCE (Load Control Embossments)

LCE refers to a specific embossment design available on some MLS head gaskets. This embossment design requires less clamp load creating less bore distortion and conforms load distribution across the sealing area.

3 Layer LCE Cross Section


AFM Gasket Material

Commonly used in transmission and engine case gaskets. AFM is the ideal gasket material for machined surfaces, especially two uneven stamped surfaces that have been plated. AFM is a chemically blown, compounded nitrile synthetic rubber bonded to an aluminum core. It has a temperature resistance of over 250F. AFM has an 85% recovery while maintaining a strong torque retention. No gaskets sealants or silicon bead is required. Re-torque is also not required.

Spring Steel

Spring Steel

Commonly used in rocker box, base, and oil pump gaskets. Our spring steel has a stainless core with .001” thick coating of FRM rubber on both sides. Ideal for machined surfaces including timing covers and rear end housings, and base gaskets.