Description

It's no secret that the OEM Subaru case halves, or "block," aren't exactly the strongest. IAG has developed a process to greatly improve the strength of the OEM Subaru EJ20 Case Halves to combat the effects of high cylinder pressures brought on by increased power and boost. Our proprietary "Closed Deck" System works by supporting the top of the cylinder in the weakest areas and prevents movement and expansion which can lead to cracks and failures. Despite the additional material supporting the cylinder walls, there is no concerns with overheating or coolant flow because the area around the middle of the cylinder still maintains the same coolant area. The custom IAG closed deck inserts are machined with holes for oil and coolant to pass through the same as stock. If you're one of those people who prefer to do your own builds we now offer our legendary closed deck case halves for purchase separately. Simply install your crank, rods, and pistons to your own specifications and be confident that the case halves will take the power and prevent common cylinder wall failures. The IAG Closed Deck conversion is performed 100% in-house by our engineers and experts using state-of-the-art equipment. The IAG Closed Deck starts with a new OEM EJ20 bare case. The case is loaded and fixtured to a 4th axis rotary indexer in our Haas VF4-SS CNC Vertical Machining Center. It is supported by the main journals using a precision ground 2-inch bar and tailstock which ensures the datum is the main journals. This method gives us a true reference point to perform all machining operations. A Rennishaw probe is utilized to check that the case is fixtured true, and once confirmed the machining process begins.

Specifications

What's Included

  • x1) IAG 1150 Closed Deck Converted Case Halves with threaded and indexed case bolt plugs (Using brand new EJ25 Case / Stock Bore 99.5mm) *99.75mm Bore and hone additional and required before final assembly!
  • (x1) Machined for 14mm Head Studs (Head Studs Sold Separately)
  • (x1) Machined for Fire-Lock™ Head Gaskets (Gaskets Sold Separately)
  • (x1) Machined for Pinned Mains
  • (x1) ARP Case Hardware Set

Compatibility

  • 2014 Subaru Forester 2.0XT Limited
  • 2015 Subaru Forester 2.0XT Premium
  • 2014-2015 Subaru Forester 2.0XT Touring
  • 2008 Subaru Forester 2.5 XT
  • 2008 Subaru Forester Sports 2.5 XT
  • 2004-2015 Subaru Forester XT
  • 2006-2013 Subaru Forester XT Limited
  • 2005-2013 Subaru Forester XT Premium
  • 2010-2012 Subaru Forester XT Sports
  • 2011-2013 Subaru Forester XT Touring
  • 2002-2013 Subaru Impreza WRX
  • 2010 Subaru Impreza WRX GT
  • 2006-2013 Subaru Impreza WRX Limited
  • 2009-2013 Subaru Impreza WRX Premium
  • 2010 Subaru Impreza WRX SE
  • 2004-2013 Subaru Impreza WRX STI
  • 2007-2013 Subaru Impreza WRX STI Limited
  • 2010 Subaru Impreza WRX STI Special Edition
  • 2006-2007 Subaru Impreza WRX TR
  • 2010-2012 Subaru Legacy 2.5GT
  • 2002-2013 Subaru Legacy GT
  • 2002-2009 Subaru Legacy GT Limited
  • 2006-2009 Subaru Legacy GT spec.B
  • 2018-2021 Subaru WRX 6 Man
  • 2012-2021 Subaru WRX Base
  • 2018-2021 Subaru WRX CVT
  • 2021 Subaru WRX EyeSight
  • 2013-2021 Subaru WRX Limited
  • 2015-2021 Subaru WRX Premium
  • 2019 Subaru WRX Raui Edition
  • 2014 Subaru WRX SE
  • 2012-2016 Subaru WRX STI
  • 2013-2021 Subaru WRX STI Base
  • 2020 Subaru WRX STI Kanrai Edition
  • 2015 Subaru WRX STI Launch Edition
  • 2015-2021 Subaru WRX STI Limited
  • 2019 Subaru WRX STI S209
  • 2018-2021 Subaru WRX STI STI
  • 2016 Subaru WRX STI Series.HyperBlue
  • 2017-2021 Subaru WRX STI Sport
  • 2013-2021 Subaru WRX STI Sport-tech
  • 2014 Subaru WRX STI Tsurugi Edition
  • 2018 Subaru WRX STI Type RA
  • 2017-2021 Subaru WRX Sport
  • 2017-2021 Subaru WRX Sport-tech
  • 2019-2020 Subaru WRX Sport-tech RS

It's no secret that the OEM Subaru case halves, or "block," aren't exactly the strongest. IAG has developed a process to greatly improve the strength of the OEM Subaru EJ20 Case Halves to combat the effects of high cylinder pressures brought on by increased power and boost. Our proprietary "Closed Deck" System works by supporting the top of the cylinder in the weakest areas and prevents movement and expansion which can lead to cracks and failures. Despite the additional material supporting the cylinder walls, there is no concerns with overheating or coolant flow because the area around the middle of the cylinder still maintains the same coolant area. The custom IAG closed deck inserts are machined with holes for oil and coolant to pass through the same as stock. If you're one of those people who prefer to do your own builds we now offer our legendary closed deck case halves for purchase separately. Simply install your crank, rods, and pistons to your own specifications and be confident that the case halves will take the power and prevent common cylinder wall failures. The IAG Closed Deck conversion is performed 100% in-house by our engineers and experts using state-of-the-art equipment. The IAG Closed Deck starts with a new OEM EJ20 bare case. The case is loaded and fixtured to a 4th axis rotary indexer in our Haas VF4-SS CNC Vertical Machining Center. It is supported by the main journals using a precision ground 2-inch bar and tailstock which ensures the datum is the main journals. This method gives us a true reference point to perform all machining operations. A Rennishaw probe is utilized to check that the case is fixtured true, and once confirmed the machining process begins.

  • x1) IAG 1150 Closed Deck Converted Case Halves with threaded and indexed case bolt plugs (Using brand new EJ25 Case / Stock Bore 99.5mm) *99.75mm Bore and hone additional and required before final assembly!
  • (x1) Machined for 14mm Head Studs (Head Studs Sold Separately)
  • (x1) Machined for Fire-Lock™ Head Gaskets (Gaskets Sold Separately)
  • (x1) Machined for Pinned Mains
  • (x1) ARP Case Hardware Set
  • 2014 Subaru Forester 2.0XT Limited
  • 2015 Subaru Forester 2.0XT Premium
  • 2014-2015 Subaru Forester 2.0XT Touring
  • 2008 Subaru Forester 2.5 XT
  • 2008 Subaru Forester Sports 2.5 XT
  • 2004-2015 Subaru Forester XT
  • 2006-2013 Subaru Forester XT Limited
  • 2005-2013 Subaru Forester XT Premium
  • 2010-2012 Subaru Forester XT Sports
  • 2011-2013 Subaru Forester XT Touring
  • 2002-2013 Subaru Impreza WRX
  • 2010 Subaru Impreza WRX GT
  • 2006-2013 Subaru Impreza WRX Limited
  • 2009-2013 Subaru Impreza WRX Premium
  • 2010 Subaru Impreza WRX SE
  • 2004-2013 Subaru Impreza WRX STI
  • 2007-2013 Subaru Impreza WRX STI Limited
  • 2010 Subaru Impreza WRX STI Special Edition
  • 2006-2007 Subaru Impreza WRX TR
  • 2010-2012 Subaru Legacy 2.5GT
  • 2002-2013 Subaru Legacy GT
  • 2002-2009 Subaru Legacy GT Limited
  • 2006-2009 Subaru Legacy GT spec.B
  • 2018-2021 Subaru WRX 6 Man
  • 2012-2021 Subaru WRX Base
  • 2018-2021 Subaru WRX CVT
  • 2021 Subaru WRX EyeSight
  • 2013-2021 Subaru WRX Limited
  • 2015-2021 Subaru WRX Premium
  • 2019 Subaru WRX Raui Edition
  • 2014 Subaru WRX SE
  • 2012-2016 Subaru WRX STI
  • 2013-2021 Subaru WRX STI Base
  • 2020 Subaru WRX STI Kanrai Edition
  • 2015 Subaru WRX STI Launch Edition
  • 2015-2021 Subaru WRX STI Limited
  • 2019 Subaru WRX STI S209
  • 2018-2021 Subaru WRX STI STI
  • 2016 Subaru WRX STI Series.HyperBlue
  • 2017-2021 Subaru WRX STI Sport
  • 2013-2021 Subaru WRX STI Sport-tech
  • 2014 Subaru WRX STI Tsurugi Edition
  • 2018 Subaru WRX STI Type RA
  • 2017-2021 Subaru WRX Sport
  • 2017-2021 Subaru WRX Sport-tech
  • 2019-2020 Subaru WRX Sport-tech RS

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