IAG Stage 4 Cylinder Head Package w/ Combustion Chamber Mod Includes GSC S2 Camshafts - 2002-2005 Subaru WRX

Please Note: This item is not eligible for standard ground shipping and must be delivered via freight. To receive a custom invoice that includes all applicable freight charges, kindly contact us by email or phone.

 

STOCK NOTICE: At times, this item carries a 6-8 week build time when not in stock. 

 

 

 

IAG Stage 4 Cylinder Head Package w/ Combustion Chamber Mod - 02-05 WRX 2.0L S20 Castings (Includes GSC S2 Cams / New Lifter Buckets)

RallySport Direct now carries highly sought-after high-performance upgrades and accessories brought to you by IAG Performance.

 

This is the IAG Performance Stage 4 CNC Ported Heads With +1MM GSC Valves And GSC Billet S2 Camshafts With Combustion Chamber Mod.

These heads utilize a CNC porting program for the S20 heads that have been developed over the past 5 years, and they have been tested on the most successful high-horsepower Subarus. These begin as brand new S20 head castings directly from Subaru Of America, where they are visually inspected and then fixtures at IAG's in-house Centroid 5-axis CNC machine which is considered to be of the most advanced piece of precision engine machining equipment available worldwide.

 

FEATURES:

• Centroid 5-Axis CNC machined in-house at IAG
• The Centroid ports the intake and hard to reach exhaust "dog-leg" port runners
• Everything starts with brand new Subaru S20 head castings that are visually inspected
• The Centroid 5-Axis offers consistent port results that are hard to achieve by hand

 

COMBUSTION CHAMBER MODIFICATION

• Once the Centroid completes the port process the heads receive the combustion chamber modification
• The shapes of the chamber are machined to reduce compression and to improve the burn path
• The heads then 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

 

COMPONENTS AND MACHINING PROCESS

• The OEM guides get pressed out
• Installed are GSC Manganese-Bronze valve guides that are shaped to improve airflow
• The intake and exhaust guides are then diamond-honed
• The heads are fixtured with IAG's Serdi 3.0 Valve Guide And Seat Machine
• All intake and exhaust seats are cut with a multi-angle valve job that suits the flow characteristics of GSC's +1mm valves
• The head decks are resurfaced using IAG's TS-3000 BlockMate that cuts the aluminum to a smooth even finish
• The heads are then ultrasonically cleaned to remove debris and oil from the machining process
• The heads are then reassembled using GSC Billet S2 camshafts

 

INCLUDES:

• (2) Brand new Subaru S20 cylinder head castings
• (8) GSC 37mm (+1mm) intake valves
• (8) GSC 33mm (+1mm) SuperAlloy exhaust valves
• (16) GSC Beehive springs and retainers
• (16) GSC Manganese-Bronze valve guides
• (16) GSC valve stem seals
• (16) OEM lifter buckets
• GSV Billet S2 Camshafts
• IAG Performance CNC porting
• Multi-angle valve job
• Drilling for compatibility for 1/2" or 14mm head studs
• Cam clearancing
• Resurface
• Ultrasonic cleaning
• Bench lashed

 

GSC BILLET S2 CAMSHAFT FEATURES:

• 272-degree intake/exhaust duration
• 234-degree intake/exhaust duration @ 0.040
• Intake/exhaust peak lift 10.25mm
• Intake center-line - 110 degrees
• Exhaust center-line 115 degrees

Note: Workmanship/parts warranty will only be available for professionally installed cylinder heads

 

IMPORTANT DELIVERY NOTE:

Your order is shipping Via Truck Freight which requires you to be available at the time of receipt. There is a possibility the trucking company will try to schedule a delivery time with you.

At the time of delivery, the driver will hand you the delivery receipt also referred to as the bill of lading, you will use this to notate any damages to the shipment. It is important that you fully inspect the shipment from all sides and notate any dents, punctures or rips in the outside packaging on the delivery receipt. Once you've inspected your shipment from the outside, you will need to open it and check the product in its entirety for damages and notate them if any.

If there is no damage sign for the package and enjoy!

In the rare case, you do find that your order arrived with damages, it is important you follow these steps.

- Do not refuse the product
- Document the damages in as much detail as possible on the Bill of Lading
- Take numerous photos from all angles (including packaging)
- Keep the product and contact the shipping company to start the damage claim
- Contact us either by phone or email for the next steps

In the situation where the delivery driver is unable to wait for you to open and inspect your product, simply document "driver was unable to wait for inspection." All damage must be noted on the Bill of Lading before signing and initiating a damage claim. If the damage is not notated before signing for the item it is assumed to be in good condition. This will forfeit the ability for a shipping claim and you will not be eligible for refund or replacement.