EJ25 - Unlimited, Sleeved Closed Deck Case Halves (Provide your own)

CJM Unlimited - SLEEVED CLOSED DECK EJ25 

The Ultimate Subaru EJ25 Foundation for Extreme Power

Each unit begins with a brand-new OEM EJ25 case that’s CNC-machined in-house for our proprietary Closed Deck conversion. Billet aluminum inserts reinforce the deck surface and upper cylinder areas — but the real strength comes from our upgraded Ductile Iron Liners, which replace the factory aluminum bores with ultra-strong, heat-resistant sleeves.

These liners provide exceptional wear resistance, thermal stability, and bore strength, allowing the block to handle extreme boost and 1150+ horsepower with confidence.

Key Features

• CJM Ductile Iron Liners: Handle extreme cylinder pressures and heat for maximum reliability and longevity.
• Billet Closed Deck Inserts: Add rigidity around the cylinders while maintaining coolant flow through integrated water passages.
• Precision Fitment: CNC machining and thermal press-fit process ensure perfect alignment and structural integrity.
• Enhanced Cooling: Engineered coolant paths prevent hot spots, keeping the engine stronger and cooler than OEM.
• Bore & Hone Ready: Machined for 99.75 mm pistons, with optional CJM  Bore & Hone Service available.

Engineered Without Compromise

Whether for a high-boost street car or a full race build, CJM Pro Mod Sleeved Closed Deck EJ25 delivers the strength, cooling, and precision your Subaru engine needs to push beyond its limits.

Built Stronger. Handles More Power.

Requires:

• CJM x P1 Mfg 14mm Head Studs
• CJM Fire Ring Head Gaskets