Cometic Subaru EJ25 Motor 100mm .051 inch MLS Head Gasket DOHC 16V - C4264-051

Cometic MLS Head Gasket — Subaru EJ25, 100mm Bore, .051" (C4264-051)

A multi-layer steel head gasket for the EJ25, and the standard fix when a factory gasket lets go on a boosted flat-four.

MLS provides maximum sealing performance and requires no sealants. Three layers of stainless steel give increased strength plus the ability to rebound and resist corrosion — that rebound is what keeps the seal alive through heat cycles instead of crushing once and staying crushed.

Load-controlled embossments conform load distribution across the sealing area, which creates an exceptional seal while requiring less clamp load and producing less bore distortion. Outer layers are embossed and coated both sides with Viton, heat resistant to 250°C / 482°F. The center shim layer is uncoated stainless, and its thickness sets the compressed height.

Applied dry. No sealant, no re-torque when properly installed on prepared surfaces.

Specs: 100mm bore, .051" compressed thickness, 3 layers, round bore. Made in USA.

Fitment: Subaru EJ25D, EJ251, EJ252, EJ253, EJ255, EJ257 — 06-14 WRX, 04-17 STI, 04-13 Forester XT, 05-09 Legacy GT and Outback XT.

Sold individually — you need two per engine. This is the single most common ordering mistake on a boxer, and it means the build stops halfway.

Two things to plan for. MLS needs a properly finished deck and head surface to seal; a wipe-down isn't enough. And thickness changes compression, so pick to your target — .040" and .060" are the other options.

Head studs are effectively required. An MLS gasket on stock head bolts under real boost is how people end up doing this job twice.