IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set

IAG Fire-Lock 2.5L Subaru Head Gaskets (1 Pair) w/ Fire-Lock Rings

For EJ25/EJ257 100mm .051" for 14mm Head Studs

The IAG Fire-Lock™ Head Gaskets represent the ultimate solution for preventing head gasket failure in high-horsepower and high-boost Subaru applications. Engineered specifically for IAG's closed deck blocks with Fire-Lock receiver groove machining, these gaskets deliver unmatched sealing performance where conventional gaskets fail.

Key Features

• Fire-Lock Technology: Proprietary receiver groove design works with machined block to prevent head gasket failure
• .051" Thickness: Precision thickness optimized for IAG closed deck applications
• 100mm Bore Compatible: Designed for 99.75mm bored blocks (100mm nominal)
• 14mm Head Stud Design: Requires 14mm head studs (sold separately)
• IAG-Spec Fire-Lock Rings: Includes precision alloy rings for complete Fire-Lock sealing system
• Multi-Layer Steel Construction: Superior strength and heat resistance for extreme applications
• High-Boost Rated: Engineered for 950+ BHP applications

Technical Specifications

• Part Number: IAG-ENG-1741
• Gasket Thickness: .051" (1.3mm)
• Bore Size: 100mm (for 99.75mm bored blocks)
• Head Stud Size: 14mm (studs sold separately)
• Material: Multi-layer steel with Fire-Lock receiver groove compatibility
• Quantity: 1 pair (2 gaskets) with Fire-Lock ring set

Compression Ratios

When used with IAG 950 Closed Deck Short Block (IAG-ENG-S950):

• 8.8:1 on B, V, and W EJ257 cylinder heads
• 9.1:1 on D EJ255 cylinder heads

Fitment

• Subaru WRX (2002-2014) - EJ25 engines
• Subaru STI (2004-2021) - EJ257 engines
• Subaru Legacy GT (2005-2012) - EJ255 engines
• Subaru Forester XT (2004-2013) - EJ255 engines

What's Included

• 2x IAG Fire-Lock .051" head gaskets
• IAG-Spec Fire-Lock alloy ring set
• Installation instructions

Why Fire-Lock Technology?

Head gasket failure is the most common weakness in high-boost Subaru builds. IAG's Fire-Lock technology solves this by using a precision-machined receiver groove in the block deck surface that works with the Fire-Lock rings to create an enhanced combustion seal. This prevents combustion gases from escaping between the cylinder and gasket, eliminating the primary failure mode in modified engines.

Installation Requirements

• CRITICAL: Engine block MUST be machined with IAG Fire-Lock receiver groove (standard on IAG closed deck blocks)
• Head Studs: 14mm ARP head studs required (sold separately)
• Block Preparation: Block deck must be machined for Fire-Lock groove - these will NOT work on standard blocks
• Professional Installation: Strongly recommended
• Torque Specifications: Follow IAG installation guidelines precisely
• Surface Preparation: Block and head surfaces must be perfectly clean and flat

Compatible Products

• IAG 950 EJ25 Closed Deck Short Block (IAG-ENG-S950)
• IAG Performance closed deck blocks with Fire-Lock receiver groove machining
• 14mm ARP head studs (required, sold separately)

IMPORTANT: These gaskets are designed EXCLUSIVELY for use with IAG Fire-Lock receiver groove machining. They will NOT function properly on standard Subaru blocks without the Fire-Lock groove machined into the block deck surface. The block must be specifically prepared for Fire-Lock technology. Professional installation and proper torque procedures are essential for optimal performance.