MLS (Multi-Layer Steel) Head Gaskets provide better heat transfer, little to no bore distortion and will tolerate high cylinder pressure applications Turbos, Superchargers and High compression. The outer stainless steel layers are coated on both sides with Viton (a fluoroelastomer 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.
AFM (Aluminum Foam Material) is the best material available for sealing engine case covers. AFM is a cross-linked, chemically blown compounded nitrile synthetic rubber, bonded to a steel or aluminum base. This material has on 85% torque retention rate that will hold torque and seal uneven and less than perfect surfaces.
AFM cover gaskets will not push out, wick or weep.
VITON seal are made from a premium blend of Viton rubber. This elastomer has the best resistance to heat, different fuels and oils.