Cometic Head Gasket Tech

Can MLS head gaskets be used with motors setup with o-rings or receiver grooves around the cylinder bores?
No. MLS head gaskets require smooth, flat and true head and deck surfaces to seal. Most of the time with o-ring setups the wire and groove fall where our gasket’s combustion seal is located; therefore, the wire will hold the gasket and not allow proper compression while the receiver grooves allow combustion gases to escape.

What surface finish is required to us an MLS head gasket?
A surface finish of 50 RA (roughness average) or finer, is recommended for a proper gasket seal. Anything rougher may conflict with the gasket design.

What head bolt/stud torque do you recommend when using an MLS gasket?
When using MLS head gaskets always refer to the manufacturer of the fastener to determine accurate torque values. Appropriate torque is critical when installing new gaskets of any kind.

Why does Cometic recommend MLS gaskets to be installed dry?
Cometic Multi-Layer Steel (MLS) head gaskets go on dry because they are coated with a sealant. Each MLS head gasket is coated with a .001" thick Viton rubber that is bonded to the outer stainless steel layers. Adding an additional sealer can hinder the performance of an MLS head gasket.

Can I order head gaskets with a different thickness and/or bore size than you have in your catalog?
Yes. Call Cometic with the engine type or Cometic standard part number (search online or in our catalog) along with the bore size and thickness you would prefer and we will create your custom gasket.