MLS Head Gasket - 2RZ/3RZ(97mm Bore x .051" Thick)
The cylinder head gasket is arguably the most important seal in an automotive engine. Since the release of the internal combustion engine, gasket
designers have specified many materials to meet this critical sealing challenge. Traditional copper and brass gaskets gave way to metal and asbestos
in the 1950's, which in turn were superseded by composite metal and impregnated fiber/graphite composites by the 1980's. However, those systems
were largely overtaken by the development of the Multi-Layer Steel (MLS) gasket in Japan during the early 1990's.
MLS gaskets remain the automotive industry's preferred method of sealing between cylinder head and engine block, as yet unmatched by any
other sealing system. Today an estimated 80 percent of new engines are designed with MLS gaskets as standard equipment, and further growth is
projected. In the MLS system, multiple thin layers of cold-rolled spring grade stainless steel are coated with 7-25 microns of elastomeric material.
The resilient elastomer is essential to the structure by providing micro-sealing of metal surface imperfections while resisting aggressive combustion
gases, oils and coolants at temperatures up to 250�C. The surfacing needs of today's engines are as complex as the engines themselves. Multi-valve
aluminum cylinder heads on cast iron blocks are a tough combination to seal because of the difference in expansion rates between the two metals. If
the surface finishes on the head and block are too rough, lateral shearing forces that occur as the engine heats up and cools down can literally scrub
a head gasket to death.
To handle such forces, a growing number of late model engines now use multi-layer steel (MLS) head gaskets. These include many Ford, Chrysler,
Honda/Acura, Mazda, Mitsubishi, Nissan, Subaru and Toyota engines. MLS gaskets typically have 3 to 5 layers of steel and are extremely tough.
But they have little conformability and require a very smooth finish on both the block and cylinder head to seal properly. OEM specifications vary, but
surface finish requirements for MLS head gaskets typically range from 15 to 30 micro inches Ra or less.
The ability to duplicate OEM surface finishes is a must on these applications, especially if OEM style MLS gaskets are being installed in the engine.
Some aftermarket replacement gaskets for these engines have a thicker surface coating that can accommodate a more "traditional" surface finish
of up to 60 micro inches Ra. But most MLS replacement gaskets require the same surface finish as the original; which means engine builders must
have surfacing equipment that can duplicate a finish that meets OEM specifications. MLS gaskets have also become very popular in racing. Most
NASCAR engines today are running MLS gaskets, and the people who are putting these engines together typically want finishes in the low teens or
even single digits! That level of smoothness can only be obtained with equipment that has the rigidity, accuracy and control flexibility to produce an
LC Engineering has the ability to produce a finish on both the head and block in house.
Contact our Tech Support Line for further information at 928-855-6341.
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