Subaru Engine Services

Quantum Performance offers multiple specialty services for rebuilding or upgrading the Subaru EJ and FA series engines and their accessories. Below are a few of the unique services we offer to compliment and improve these platforms, whether you are simply re-conditioning or building for more power.

  • OEM or Upgraded Pre-Assembled Short-Block Options (Including our very own best selling Stage 2)
  • Cylinder Head Reconditioning Service
  • Over-Sized Valve Upgrades
  • Aftermarket Cam Installation and Valve Lash
  • CNC'd EJ20 to EJ25 Cylinder Head Chambering Service (For EJ25 block conversion)
  • Breather Port Conversion Kit (For EJ25 block conversion)
  • Porting and Polishing Services
  • Oversized Head Stud Machining and Gasket Fitment
  • CNC'd or Hand Polished OEM or Aftermarket TGV Delete Service
  • AVCS Cam Gear Rebuilding and Strengthening Service (Including Exhaust Gears for the 2008-2018 STI's!)
  • Cylinder 4 Cooling Passage Upgrade
  • Fully Balanced Rotating Assembly (Including External Items)
  • Stock Turbocharger Rebuilds or Upgrades
  • VF Turbo Porting Service (To prevent boost creep)
  • Stainless Steel Oil Lines (Turbo and Power Steering)
  • Timing Guide and Cover Conversion Kits (For A/T WRX EJ25)
  • Oil Pump Upgrade Options
  • Oil pan, Pickup, and Windage tray options


CNC'd EJ20 Chamber

EJ20 Chambering 

Custom CNC'd chamber for 2.5L Bore and 1mm Oversized Valves


EJ20/25 TGV Service

CNC'd OEM Cast TGV Housing


Porting / Polishing