EJ25 - Pro Mod, Sleeved, Long Block

EJ25 - Pro Mod, Sleeved, Long Block

Made to Order

Expected Lead Time: Feb 2026

Contact Us for Pricing

CJM-ENG-E25-32-201

CJM Pro Mod - SLEEVED EJ25 

The Ultimate Subaru EJ25 Foundation for Extreme Power

Built for serious horsepower and boost, the CJM Pro Mod Sleeved Closed Deck EJ25 is the strongest, most durable Subaru block foundation we’ve ever produced.

Each unit begins with a brand-new OEM EJ25 case that’s CNC-machined for sleeves. 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 950+ horsepower with confidence.

Key Features

  • CJM Ductile Iron Liners: Handle extreme cylinder pressures and heat for maximum reliability and longevity.
  • Precision Fitment: CNC machining and thermal press-fit process ensure perfect alignment and structural integrity.
  • 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 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

Additional Upgrades available:

  • Pinned Mains
  • Upgraded CJM Pro Mod Piston Ring Pack (For Race Gas and Ethanol) **NOT FOR STREET USE**

Build Overview

HP Capability

950

Installed Piston

CJM Pro Mod x JE Forged 2618

Connecting Rods

CJM x Callies Ultra Enforcer +2mm Length with ARP625+ Bolts

Crankshaft

OEM 2017+ STI, Nitride Coated (Optional Callies 79mm)

Combustion Gas Seal

CJM Fire Ring

Camshaft

 -

Intake & Exhaust Valve

 -

Valve Spring & Retainers

 -

Vehicle Compatibility

No vehicle compatibility information is available for this product. Contact us for more information.

Included & Additional Info

Case Halves -Converted to Sleeved Closed Deck using brand new Subaru OEM case halves, bored and honed to 99.75mm.

  • Machined for 14mm Head Studs

Sleeves (Liners)
CJM High Strength Ductile Iron Liners

Pistons
CJM x JE 99.50mm 2618 Forged Pistons, Ring Set, .250" H13 Tool Steel Wrist Pins, Clips, (Coated Skirts and Offset Wrist Pins)

Connecting Rods
CJM x Callies Ultra Enforcer +2mm Length with ARP 625+ Rod Bolts.

Rod /Main Bearings
CJM x Daido Metals or ACL

Crankshaft
Nitride Treated 2017+ STI Crankshaft

Case / Main Bolts
OEM Subaru

Compression Ratios:
Using .051" Fire Ring Head Gaskets
8.8:1 — EJ257 “B”, “V”, “W” Heads
9.1:1 — EJ255 “D” Heads

Features of the CJM Closed Deck Block

Precision Machined Closed Deck Inserts and Case Halves

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Draw attention to the care and craftsmanship that went into its design and development, setting it apart in terms of quality and attention to detail.

CJM Components gold anodized closed deck insert for EJ25

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Integral Cooling Jacket

Achieve superior engine cooling with our advanced CJM closed deck insert, designed with a radial cooling jacket and coolant pass thru holes.

Get more water surrounding the cylinder

Highlight key qualities of the product, such as the materials, ingredients, or components used. Emphasize durability, reliability, or performance in everyday use.

Draw attention to the care and craftsmanship that went into its design and development, setting it apart in terms of quality and attention to detail.