Stage X EJ20 Multi Layer High Performance Cylinder Head Gasket

Engineered for extreme conditions, these cylinder head gaskets are rated for use up to and over 800 BHP.

Unlike most conventional head gaskets, they use a folded stopper layer. The gasket is thicker around the vital sealing areas, and this extra layer forms a much stronger barrier that greatly reduces the chance of gases, pressure, water or oil escaping from where they should be. It is highly recommended for any Subaru, especially those running above standard factory torque and power figures.

The gaskets also have a nitrile rubber coating. It acts as a cushion that fills any imperfections in the cylinder head or block faces, giving a better seal around the combustion chamber.

All gaskets are die stamped rather than laser cut. Die stamping processes a large amount of material at once, so quality varies far less from one gasket to the next than with laser cutting, where each section is cut separately. Die-cut edges are also smoother and neater than the sharper edges left by laser-cut steel.

For the best seal, the gaskets are designed to accept the larger 12mm and 14mm cylinder head studs. The standard cylinder head bolt, which joins the head to the block and provides the force that holds the gasket in place, is 11mm thick with a relatively fine thread. It was developed for a mainstream engine producing no more than 320 bhp and was never intended for higher outputs, so stronger replacements should be considered.

Stage X manufactures both 12mm and 14mm head stud and nut kits. The studs are stronger thanks to their extra thickness and better material quality, and their coarser rolled thread allows a higher tightening load. This gives a much higher clamping force between the head and block faces, where the gasket sits.

Reliability is key to any engine rebuild. Whether it is a high-power build or a simple repair or refresh, choosing components carefully avoids repeating the job later.

Two gaskets are required for a Subaru engine build.