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Remanufactured Engines

M45 EJ257 Premium Remanufactured Long Block for 2004-2021 Subaru STI

In stock
Engine Model
Head Studs
Connecting Rods
Oil Pan Option
Add STI 11mm Oil Pump
Timing Components Installed
Gasket Kit
Base price$6,895.95
Options$0.00
Total$6,895.95
Deposit due now$500.00
Balance due later$6,395.95
  • Base price shown excludes option upcharges; all options are priced separately.
  • Base price shown excludes tax and shipping (if applicable).
  • A core return is required within 30 days. A $1,250 charge applies if your core is not returned.
  • Freight is charged up front for both outbound shipping and core return.

EJ257 Long Block Refined

The EJ257 is Subaru’s flagship turbocharged engine, powering the STI lineage for nearly two decades. Known for its strong semi-closed deck design and immense tuning potential, the EJ257 has become the foundation for countless high-horsepower builds while maintaining daily-drivable reliability when properly assembled.

Addressing OEM Weak Points

Ringland Failures
A known issue in higher-boost applications; upgraded forged pistons dramatically improve strength and longevity.
Bearing Wear
Improved oil clearances and hardened bearings help prevent premature wear in performance applications.

Precision Machining

Using seasoned case halves, the EJ257 case undergoes a complete bore and deck process. Cylinders are precision bored and honed with torque plates installed to simulate real-world operating stresses, ensuring perfect piston-to-wall clearances and head sealing.

Built for Durability

At the core of this long block is a nitrided OEM Subaru STI crankshaft, engineered to withstand high RPM and boost. Resized connecting rods paired with ACL or King hardened rod and main bearings provide a stable rotating assembly capable of handling serious power.

Wiseco Forged Pistons

Wiseco forged pistons replace factory cast units to significantly increase strength and detonation resistance. Combined with high-quality piston rings and seals, these pistons improve compression stability and oil control under extreme conditions.

Remanufactured Cylinder Heads

Cylinder heads are fully remanufactured, including resurfacing, valve job, lash adjustment, and installation of new valve guides and valve stem seals. Heads are assembled with MLS head gaskets and torqued to factory specifications.

Secured with ARP

ARP head studs are thread-rolled after heat treatment, increasing fatigue strength by up to 1000%. This provides superior clamping force, making them essential for high-boost STI applications.

To Sum It Up

  • Seasoned EJ257 case halves
  • OEM STI nitrided crankshaft
  • Wiseco forged pistons with new rings and seals
  • Resized connecting rods
  • ACL or King hardened rod and main bearings
  • ARP 2000 head studs
  • MLS head gaskets
  • Valve lash set
  • New valve guides and valve stem seals
  • Fits STI 2004-2021

Warranty

M45 Automotive warrants this engine against defects in workmanship and materials for 24 months or 24,000 miles (whichever comes first) from the date of receipt.

Core Charge & Freight

No up-front core charge is required. Customers must return their original EJ257 long block within 30 days of receipt. Failure to return the core will result in a $1,250 charge and voided warranty. Freight is charged up front for both outbound and return shipping to eliminate surprises.