How to Choose the Right Head Gaskets
MLS Versus Copper - Headgaskets Explained
There are many brands and many different types of head gaskets to pick and choose from. I will be giving you a most basic run down of the basic kinds available to us folks in the performance world. Most can be found in many different thicknesses to alter the compression ratio and “tune” the engine to changing conditions.
MLS gaskets are very popular especially for any modified engines. These gaskets are designed for higher compression ratios, special cam timing and higher temps (operating). MLS stands for multi-layer steel. This design behind it and the goal behind MLS is to practically eliminate distortion and blows outs, as well as added durability. MLS gaskets also have more vertical recovery which cannot be seen however can be measured. MLS gaskets act somewhat like a valve spring, as the head lifts away from the block the inner layers of the gasket push the outer layers apart to maintain the seal. We do not recommend re-using these gaskets. Modern day MLS gaskets made by performance companies also offer wire ring reinforcement which gives the two surfaces the highest amount of sealing power around the combustion chamber.
Copper gaskets are most commonly used in extreme racing conditions. Coppers natural properties allow it to distribute heat evenly to minimize the potential to warp. These gaskets also conform to warped surfaces. (not a band aid we recommend). Some gaskets may also have embossed edges to create a tighter seal and prevent blow outs something that is crucial when you're at the track. Copper headgaskets are also recommended at high compression ratios or EXTREMELY HIGH BOOST! Copper’s properties also help prevent hot spots that can cause detonation and preignition. The drawback between copper and MLS is going to be price, and most times installation issue as they need to be retorqued and sometimes sprayed with an adhesive to create a solid bond and seal. When picking out either headgasket you +1/-1MM of room to choose from dependent on bore size. I.e if you have a 89.00MM evo x 2.4 stroker you can either use a 90MM gasket or a 88MM gasket.