Stage X EJ20 2008+ Multi Layer High Performance Cylinder Head Gasket

Stage X multi-layer cylinder head gaskets are engineered for the most extreme conditions and are rated for use up to and over 800 BHP.

Unlike most conventional head gaskets, they use a folded stopper layer. This design greatly reduces the chance of pressure leaking from the cylinders. Extra thickness around the vital sealing areas forms a much stronger barrier that keeps gases, pressure, water and oil where they belong. It is highly recommended for any Subaru, especially those running above the standard factory torque and power figures.

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

All gaskets are die-stamped rather than laser cut. Die stamping processes a large amount of material at once, so quality varies far less between individual gaskets than with laser cutting, where each gasket 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 larger 12mm and 14mm cylinder head studs. The standard head bolt, which joins the head to the block and provides the clamping force for the gasket, is 11mm thick with a relatively fine thread. It was developed for a mainstream engine producing no more than 320 BHP, so stronger replacements should be considered above that level. Stage X makes both 12mm and 14mm head stud and nut kits. The studs are stronger thanks to their extra thickness and better material quality, and their much coarser rolled thread allows them to be tightened far more than the standard bolt. This gives a much higher clamping load between the head and block faces where the gasket sits.

Whether an engine is rebuilt for more power or simply repaired or refreshed, components should be chosen carefully so the job does not have to be repeated later.