With multi-layer steel, or MLS, head gaskets all the current rage, Fel-Pro designed in a few key innovations to differentiate its PermaTorqueMLS line from the rest of the field.

“We have four layers: three active with one shim,” explains Ron Rotunno. “There’s also a stopper layer laser-welded to the shim. Together they form a ‘spring’ to maintain contact pressure between the block and head.”

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Fel-Pro's MLS head gaskets feature three active layers and one shim (left). Shown is the laser-welded stopper layer on the shim (right).

MLS is the latest in a line of gasket technology that has improved to keep pace with increasing cylinder pressures in performance engines. In the early days it was copper shims followed by single-layer embossed steel. Then came composite gaskets with wire-ring seals. Now MLS is used by all the top race teams and is now the industry standard on factory engines.

“The key is understanding the engine and where the head lift occurs,” says Rotunno. “We focus on those areas.”

Embossing the gaskets is also an engineering art as the height, width and radius of the raised area are critical. Fel-Pro conducted extensive FEA tests to confirm the designs. The stainless-steel gaskets also receive a blue coating to help enhance sealing.

“It’s really a dynamic piece,” adds Rotunno.

Fel-Pro also showed off a new line of intake manifold gaskets under the PermaDryPlus brand. While many OEM intake gaskets have a plastic carrier, the Fel-Pro models feature an aluminized steel carrier with proprietary rubber sealing compounds that can withstand all types of coolants.

In designing the PermaDryPlus gaskets, Fel-Pro engineers disassembled numerous junkyard motors to locate trouble spots.

“We have multiple sealing beads around the intake ports,” says Rotunno. 

Other features of the PermaDryPlus gaskets include locating tabs to assure proper positioning and self-centering torque limiters.