Cometic H1631SPK051S MLS Head Gasket for Subaru EJ22/EJ25 Hybrid DOHC 16V 100mm

Vehicle Fitment

• Subaru EJ22/EJ25 Hybrid Motor - EJ22E Block with EJ25D DOHC 16V Cylinder Heads (100mm Bore)
• Compatible with Subaru Impreza, Legacy, Outback, and Forester platforms using the EJ22/EJ25 hybrid engine combination

Fitment Notes

• Designed specifically for the EJ22/EJ25 hybrid build - EJ22 short block paired with EJ25D DOHC 16V cylinder heads
• 100mm bore - verify bore size before ordering; does not fit stock EJ22E (99mm bore) or standard EJ25 SOHC applications
• Not designed for use on engines with O-rings or receiver grooves
• Sold individually - one gasket per package; two required for a complete engine build
• Surface finish of 50 Ra or finer recommended for proper MLS gasket seal

Features

• Multi-Layer Steel (MLS) construction with embossed stainless steel layers and Viton fluoroelastomer rubber outer coating
• Heat resistant to 250°C / 482°F - well suited for high-output and boosted applications
• No sealants required and no re-torque needed after initial break-in
• Ideal for both aluminum head-to-aluminum block and aluminum head-to-cast-iron block pairings
• Reduces bore distortion through even clamp load distribution across the sealing surface
• Available in multiple thickness options to tune compression ratio on hybrid builds
• Made in the USA to Cometic's exacting performance standards
• Engineered for high-boost turbo builds as well as naturally aspirated performance applications

Specifications

• Part Number: H1631SPK051S
• Material: Multi-Layer Steel (MLS)
• Bore Size: 100mm (3.937")
• Bore Shape: Round
• Compressed Thickness: 0.051"
• Outer Layer Coating: Viton fluoroelastomer rubber (.001" bonded)
• Engine Application: Subaru EJ22/EJ25 Hybrid - DOHC 16V
• Position: Cylinder Head Gasket

Included Components

• 1x Cometic MLS Cylinder Head Gasket (H1631SPK051S)

Product Description

The Cometic H1631SPK051S is an MLS cylinder head gasket engineered for the popular Subaru EJ22/EJ25 hybrid engine combination - pairing an EJ22 short block with EJ25D DOHC 16V cylinder heads at a 100mm bore. At 0.051" compressed thickness, this gasket is well suited for builders looking to maintain near-stock compression while achieving a reliable, high-performance seal on this hybrid platform.

Built from multiple embossed layers of spring stainless steel with Viton-coated outer surfaces, the H1631SPK051S requires no sealants and no re-torque after break-in. It performs equally well in naturally aspirated builds and boosted applications, making it a trusted choice for Subaru enthusiasts building high-output EJ hybrid motors.