Stage 3 EJ257


Our Stage 3 motor is where things get fun. Manley is a leader in providing quality parts across the Subaru platform, but they did an exceptional job with the EJ series cranks. Lightened, knife edge, and highly toleranced, you get huge gains and reliability with a Manley forged crank. Due to the stiffer nature of the Manley crank, we can control the clearances much better for the bearings, giving the owner more HP and better life. We will provide a hard copy spec sheet and blueprint with this motor, and if requested an electronic copy. Our goal is to provide the customer, you, with entry to a level of engine building normally found in super cars and race teams. Our goal is your success, we are not afraid of any problem, and will assist you with any questions. Something that we do that goes above what is traditionally found in a motor at this price point;

  1. Press Fit Insert with more efficient cooling capacity
  2. Pin the Mains with a press-fit dowel pin
  3. Provide true fully blueprinted motor

Blueprinting, Balancing, and Inspection Notes

We blueprint the entire assembly of the motor to within .0002 of our specs,” we then balance the rotating assembly to 1g. Even though the H4 motor is inherently self-balancing, it is incredibly important to balance your motor to increase the life of your bearings. We have an in-house crank balancer with bob weights to give exacting results. It is highly recommended to run a Fluidampr crank pulley or OEM. Do not run an aftermarket solid crank pulley. All of our inspection equipment is high quality, either from Starrett or Mitutoyo, and is sent off yearly for calibration to a qualified cal-lab.



  • Brand New OEM Inserted Case Halves bored out to 99.75mm and align honed to exacting dimensions. We pin the mains and use decking plates and fixtures to match the distortion the engine will see during final assembly. Once complete, we deck the completed case halves to create a true plane for your head gasket to properly seat on.
  • Manley Turbo Tuff Series Pistons- Please Specify Desired Compression Ratio, stock is 8.5.
  • Manley Turbo Tuff Forged Rods w/ 625+ bolts.
  • Clevite Coated, ACL or King Race Bearings for rods and mains- Please give us details on where and how this motor is intended to be used. Clearances will change pending your intended use.
  • Brand New Manley Forged Crank – balanced in house. Offered in 75mm, 79mm and 83mm strokes.If you would like a true balanced RA, please send us your intended flywheel.
  • Brand New OEM Subaru Case Bolts or ARP Case bolts on request.
  • Brand New OEM Cover and Seal Kit- No we don’t charge extra