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IAG Performance Magnum EJ20 Short Block Magnum EJ20 Subaru Closed Deck Short Block

Engine Short Block


IAG Magnum EJ20 Subaru Closed Deck Short Block for 02-05 WRX.

  • 14mm Head Studs are REQUIRED (Sold Separately)
  • All IAG short blocks are balanced and blueprinted.
  • Compression Ratio: 8.5:1 on S20 Cylinder Heads (EJ20)
  • Head Gasket Required: IAG Fire-Lock .051" Head Gaskets with IAG-Spec Alloy Ring Set, PN# IAG-ENG-1745 are REQUIRED (Sold Separately).
  • The IAG Magnum Short Block has a power output rating of 900BHP
Pricing: $5,999.99

Free ground shipping on all order over $100.00 (some exclusions may apply)


Subaru: Impreza 02 - 05 WRX

  • 14mm Head studs are REQUIRED and sold separately,
  • IAG Fire-Lock head gaskets REQUIRED
  • IAG Magnum Closed Deck Includes: Case Halves -Converted to Closed Deck using brand new Subaru OEM case halves, bored and honed to 92.5mm, Fire-Lock -IAG Fire-Lock receiver groove machining, latest solution to prevent head gasket failure on high horsepower and high boost Subaru's - Head Studs -Machine Case for 14mm head studs - Pistons -IAG-Spec JE FSR 92.5mm 2618 Forged Pistons, Electroless Nickel Plated Tops & Ring area, Ring Set, .250" / .906" H13 Wrist Pins, Clips, (Perfect Skirt Coating and Offset Wrist Pins), Connecting Rods -IAG-Spec Tuff H-Beam +2mm / ARP 625+ Rod Bolts, Rod / Main Bearings -ACL or King Race bearings, Crankshaft -New Subaru EJ20 WRX Crankshaft with improved oil passages, Case / Main Bolts -Standard FHI Subaru case bolts.

IAG Magnum Subaru EJ20 Closed Deck Short Block. The IAG Magnum EJ20 Short Block starts with brand new Subaru 2.0L 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 Magnum 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 92.5mm 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 Subaru 2.0L crankshaft with improved oil passages that is matched to ACL or King race main bearings. IAG-Spec Tuff H-Beam +2mm connecting rods 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 92.5mm 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 Magnum short block. Additionally, all IAG-Spec piston skirts utilize the JE Perfect Skirt coating.


  • IAG-ENG-1281
  • IAG-ENG-1281
  • 887753780829
  • IAG Performance
  • New


Shipping Information

  • Item Requires Shipping
  • 105.0 lbs.
  • W19.0000” x H16.0000” x L19.0000”
  • Free ground shipping on all order over $100.00 (some exclusions may apply)

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