IAG Performance IAG-ENG-1452 Stage 4 Tuff EJ25 Subaru Closed Deck Short Block

IAG Stage 4 Tuff Subaru EJ25 Closed Deck Short Block The IAG Stage 4 Tuff Short Block starts with brand new Subaru 2.5L engine case halves. IAG machines the case halves assembled together in our Haas VF-4SS CNC mill to accept the IAG CLOSED Deck Inserts that transform the block into a solid deck. The unique inserts feature small passages that allow needed coolant flow to the deck surface. The case halves are then CNC machined for our new Fire-Lock head gasket solution that is loosely derived from diesel technology where a counterbore step is machined around each cylinder bore allowing specially sized fire rings to drop into the machined area and head gasket bores. The Stage 4 Tuff case is then drilled and tapped to accept 14mm head studs that combined with the IAG Fire-Lock head gasket set greatly reduces head gasket failure during high cylinder pressure scenarios. Next, the short block is Deck Plate bored and honed to 99.75mm in our in-house Sunnen SV-30 the most advanced automotive cylinder hone available. IAG's in-house honing process is able to set custom piston to wall clearances to best fit your needs. The modified case halves are then assembled using a new 2017+ Subaru 2.5L nitride treated STI crankshaft that is matched to ACL or King race main bearings. Custom IAG TRI-BEAM +2mm connecting rods by Manley and ARP 625+ rod bolts are utilized along with ACL or King race rod bearings. The case halves are sealed with new OEM main/case bolts and sealant (upgrading to ARP mains requires line honing). Finally, IAG-Spec 99.75mm JE FSR 2618 Forged Pistons with electroless nickel plated tops and ring area as well as upgraded .250" / .906" H13 wrist pins are added to finish the Stage 4 Plus block.

This Part Fits:

Year	Make	Model	Submodel	Notes
2005	Saab	9-2X	Aero
2006	Saab	9-2X	Aero
2004	Subaru	Baja	Turbo
2005	Subaru	Baja	Turbo
2006	Subaru	Baja	Turbo
2010	Subaru	Forester	XT Sports
2011	Subaru	Forester	XT Sports
2012	Subaru	Forester	XT Sports
2011	Subaru	Forester	XT Touring
2012	Subaru	Forester	XT Touring
2013	Subaru	Forester	XT Touring
2009	Subaru	Impreza	2.5 GT
2010	Subaru	Impreza	2.5 GT
2002	Subaru	Impreza	WRX
2003	Subaru	Impreza	WRX
2004	Subaru	Impreza	WRX
2005	Subaru	Impreza	WRX
2006	Subaru	Impreza	WRX
2007	Subaru	Impreza	WRX
2008	Subaru	Impreza	WRX
2009	Subaru	Impreza	WRX
2010	Subaru	Impreza	WRX
2011	Subaru	Impreza	WRX
2012	Subaru	Impreza	WRX
2013	Subaru	Impreza	WRX
2014	Subaru	Impreza	WRX
2009	Subaru	Impreza	WRX Premium
2010	Subaru	Impreza	WRX Premium
2011	Subaru	Impreza	WRX Premium
2012	Subaru	Impreza	WRX Premium
2004	Subaru	Impreza	WRX STI
2005	Subaru	Impreza	WRX STI
2006	Subaru	Impreza	WRX STI
2007	Subaru	Impreza	WRX STI
2008	Subaru	Impreza	WRX STI
2009	Subaru	Impreza	WRX STI
2010	Subaru	Impreza	WRX STI
2011	Subaru	Impreza	WRX STI
2012	Subaru	Impreza	WRX STI
2013	Subaru	Impreza	WRX STI
2014	Subaru	Impreza	WRX STI
2006	Subaru	Impreza	WRX TR
2007	Subaru	Impreza	WRX TR
2011	Subaru	Legacy	2.5GT
2012	Subaru	Legacy	2.5GT
2006	Subaru	Legacy	GT spec.B
2007	Subaru	Legacy	GT spec.B
2008	Subaru	Legacy	GT spec.B
2009	Subaru	Legacy	GT spec.B
2005	Subaru	Outback	XT
2006	Subaru	Outback	XT
2007	Subaru	Outback	XT
2008	Subaru	Outback	XT
2005	Subaru	Outback	XT Limited
2006	Subaru	Outback	XT Limited
2007	Subaru	Outback	XT Limited
2008	Subaru	Outback	XT Limited
2009	Subaru	Outback	XT Limited
2015	Subaru	WRX STI
2016	Subaru	WRX STI
2017	Subaru	WRX STI
2018	Subaru	WRX STI
2019	Subaru	WRX STI
2020	Subaru	WRX STI
2021	Subaru	WRX STI