Subaru Pro-Built Engines

Subaru Performance Engine Building Services

Forged Bottom Ends, Stroker Motors, Iron Sleeved Cylinders, Head Packages & More

Subaru STi

Simply put – we’ve been at this for a very long time! After investing a lot of our time and resources, we have identified several problem prone areas within the factory motor design that limit your fun-factor. You can rest assured, that our horsepower specification that we’ve associated with our in-house built motors still leaves some head room.

We choose our rod and main bearing clearances based on the ultimate RPM range that your new motor will see. We also give you the choice to choose your engine compression ratios. You have two choices of 8.5:1 or 9.8:1 and whichever you choose, please keep in mind of the type of fuel that the motor will see most often. This is an important part when ordering your motor. Typically, we’ll suggest the higher compression to run on race gas or E85.Manley-Logo-website

Since Motion Lab is a wholesale distributor for Manley Performance and has established relationships with other major engine parts manufacturers, we are able to provide the most proven and reliable combination of Subaru engines on the market.

Additional build information: Motion Lab typically implements the use of a torque plate for our performance line of motor builds (not used for standard rebuilds). Our build tolerances are repeatedly checked throughout the build process, which includes:

  • Individual (ring to bore) ring end gaps augmented
  • Individual piston-bore clearances checked
  • Wrist pin bore checked
  • Main, rod, and thrust bearing clearances checked
  • Strict rod bearing eccentricity measurements
  • Big-end rod bore roundness checked
  • Small-end rod bore checked
  • Crank straightness checked
  • Block decks checked

Subaru EJ255/257 (04-Present)

Subaru FA20 (15-Present WRX)