Atomic Barra MLS-D Headgasket
Engineering Overview
SPEC-DOC
Atomic MLS-D Head Gasket
The Problem with Standard Gaskets
Standard Multi-Layer Steel (MLS) gaskets are functional for street cars, but under the extreme cylinder pressures of high-boost racing, the layers can be split apart by combustion pressure. This will eventually break the seal, leading to coolant leaks and combustion pressure loss. In a high-horsepower Barra, a standard gasket is often the fuse that blows first.
"MLS-D" stands for Diesel Style. Unlike a standard MLS gasket where layers are merely stacked, an MLS-D gasket folds the outer steel layers back over the center core at the cylinder bore. This creates a super-strong, continuous integrated fire ring that is virtually impossible to blow out under boost. Compatible with 14mm head studs.
The Atomic Solution
We've standardized the MLS-D Head Gasket across our premium performance range. At 1.00mm thick with a folded bore architecture, this gasket offers the sealing capability of a wire O-ring setup without the need for expensive, permanent block machining. It is the ultimate "drop-in" insurance policy for your Barra build.


Engineered for Extreme Pressure
The MLS-D design is the result of years of testing in extreme-load environments.
- 3-Layer Steel Construction: High-grade stainless steel layers provide excellent thermal expansion characteristics.
- Folded Bore (Fire Ring): The folded outer layer creates a massive localized "crush" area, maximizing seal pressure where combustion gasses need it most.
- High-Temp Coating: Premium polymer-based coating on the outer layers ensures a perfect seal against the block and head casting imperfections.
Tech Specs
Head Gasket Type: MLS-D (Diesel Style Folded)
Thickness: 1.00mm Compressed
Construction: 3-Layer Stainless Steel with Fire Ring Fold
Compatibility: Ford Barra DOHC 4.0L (BA-FGX)
⚠️ Important Fitment Guide
- Compatible with 12mm (STD, ARP, Atomic, etc.) and 14mm (Atomic) head studs
- Deck Surface: For the best seal with this gasket, ensure your block and head are machined to an RA finish suitable for MLS gaskets (typically < 30 RA).
- Whilst copper spray/Hylomar are not required, we regularly use it for additional security and help with sealing in marginal areas.