Stage 5 CNC Ported Heads w +1mm Ferrea Valves & GSC S3 Cams N25 Casting – IAG-ENG-3055NS4 Discount

IAG s Stage 5 Cylinder Head Package utilizes a CNC porting program for the N25 heads that was developed over the past five years and tested on the most successful high-horsepower Subaru s. The ported head package starts with brand new N25 OEM WRX STI head castings directly from Subaru of America. The bare castings are visually inspected then fixtured into our in-house Centroid 5-axis CNC Machine, one of the most advanced precision engine machining equipment in the world. The Centroid CNC ports the intake and hard to reach exhaust dog-leg port runner. CNC porting is not only an efficient way of machining the heads and offers consistent port results every time. Once the Centroid completes the port process the heads undergo a cam clearance machining process that removes material from the lifter area where large duration cam profiles are known to contact the castings. Short after the heads are drilled to fit larger 1 2 or 14mm head studs which are commonly used in high horsepower builds. Next, the OEM guides are pressed out and replaced in favor of Ferrea Copper Bronze valve guides that are shaped to improve airflow. Once all the new guides are in place they are diamond-honed in our honing station. The heads are then fixtured in our Serdi 3.0 Valve Guide and Seat Machine to cut all intake and exhaust seat with multi-angle valve job that suits the flow characteristics of Ferrea +1mm valves. At this point, the heads decks are resurfaced using our TS-3000 BlockMate that cuts the aluminum to a smooth even finish. After resurfacing, the heads are ultrasonically cleaned to remove debris and oils from the machining process. The heads are then reassembled using GSC Billet S3 camshafts designed for drag racing applications intending to make 750-1000 wheel horsepower. During final assembly, the cams are matched to Ferrea Dual Valve Springs and Titanium Retainers along with Ferrea valve stem seals then bench-lashed to a tolerance that is close to final specifications.. Fits Subaru: WRX STI 18 – 21 Kanrai Edition Sport-tech Sport STI Type RA Limited Base S209