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IAG Stage 3 Extreme EJ25 Closed Deck Case - 1/2" H.S.M., O-ringed, (No Bore / Hone) - For Subaru WRX, STI, FXT & LGT

$2,399.99
IAG-ENG-1814

Description

Please Note: Overbore must be performed (99.75mm is the preferred bore) before assembly!

IAG's Stage 3 Extreme Closed Deck converted case halves were created to be the most affordable, cost-effective short block modification for the Subaru EJ25 turbo engines. The deck surface is machined to accept specially CNC’d cast inserts that strengthen the weakest point of the OEM case at the upper sleeve. The case halves are then CNC machined with O-ring receiver grooves around the bore surface as well as drilled and tapped to accept 1/2" head studs that greatly reduce head gasket failure during high cylinder pressure scenarios. IAG’s Stage 3 Extreme Closed Deck is suitable for street or race use.

What is a Closed Deck Block and why do I need it?

The factory Subaru EJ25 case is referred to as a semi-open (or semi-closed) deck. The block is essentially an open deck with 3 narrow supports tying in the main case to the tops of the sleeves. This feature was a slight improvement over the EJ20 case, which was a completely open deck with no support. The purpose of the deck supports is to keep the sleeve from moving. While conceptually this is an improvement, the reality is that it simply isn’t enough for a high horsepower Subaru. The weakest point of the sleeve is still left open and unaddressed.

Included:

(x1) IAG's Stage 3 Extreme Closed Deck Converted Case Halves (Using brand new EJ25 Case / Stock Bore 99.5mm) *Bore and hone additional and required before final assembly!

(x1) Machined for 1/2" Inch Head Stud conversion (1/2" Head Studs sold separately)

(x1) Machined and O-ringed Deck Surface

Additional Options:

(x1) IAG 1/2" Inch Head Stud Set (PN# IAG-ENG-1700) - Available Separately

Head Gasket Recommendations:

*IAG Recommends JE Pro Seal .039 inch head gaskets

JE PN# SB1001-039 are for use with S20, B25 & D25 Cylinder Head Castings (04-06 STI, 06-14 WRX, 04-13 FXT, 05-12 LGT, 02-05 WRX)

JE PN# SB1003-039 are for use with V25, W25 & N25 Cylinder Head Casting (2007-19 STI)

If using on 2002-05 Subaru EJ20 2.0L WRX additional modifications and parts are required.

Please Note: Overbore must be performed (99.75mm is the preferred bore) before assembly!

*Attention: Special note about using ARP Case Bolts - IAG recommends line honing the case when using ARP Case Bolts to remove any distortion created by the hardware. IAG installs ARP CASE BOLTS with 30W engine oil using OEM SUBARU torque specs and procedures. Other torque specs and lubricants may lead to case distortion damage.



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The car parts world is still feeling the impact from the Covid buying spree and shut down. Thanks to amazing customers like you, we are currently experiencing a high volume of orders and shipping may be delayed. DRP remains fully committed to pursuing the completion of your purchase within a reasonable manner under the current circumstances. You can always contact our customer service via email with questions, or to check for availability!

Please note: Not all orders will experience a delay, however, we want to continue to be as open and transparent as possible should you experience a longer than average order processing time. As a small business, your continued support means the world to us and your choice to shop with us has made a huge impact and we greatly appreciate you and your understanding!

This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov