Grimmspeed EJ25 Headgasket Set .78mm Thickness 2008-2021 STI

Feature-packed, these gaskets are a perfect fit for any engine build, from basic refresh to a high horsepower track monster. 

The GrimmSpeed Head Gaskets feature a multi-layer steel (MLS) construction, in which multiple grades are used to provide optimal surface and combustion chamber sealing as they are torqued down. The top and bottom layers feature a Nitrile Rubberized Coating that helps accommodate a rougher RA surface finish of up to 50microinch. This acts to better seal the non-critical areas of the gasket. In addition, the gasket edge includes a folded stopper layer that allows for optimal sealing for the combustion chamber. This is done to help reduce the chances of combustion gasses causing head gasket failures under extremely high cylinder pressures that built engines can experience.

After talking to numerous engine builders/tuners it was clear that creating a variety of gasket thicknesses was key for pairing them with the right build. With that in mind, we’ve made the gaskets available in multiple thicknesses (.78, 1.1, 1.5mm) to help fine tune each individual build. In addition, the slightly oversized bore diameters will allow for up to 0.5mm overbore.

The EJ specific gaskets include enlarged center head bolt holes to accommodate up to a 13mm head studs. This is a popular upgrade option for many higher power builds, where additional cylinder head clamping force is needed.