IAG Performance 1000 Series FA20 Closed Deck Short Block 2015-2021 WRX

IAG Performance 1000 Series FA20 Closed Deck Short Block 2015-2021 WRX

IAG Performance part IAG-ENG-S1020 is a 1000 Series closed deck FA20 short block for the 2015-2021 Subaru WRX. IAG rates it to support up to 1000 BHP in high-boost street, drag and track builds. A closed deck conversion and forged internals let it handle cylinder pressures far beyond the factory block.

Build details

• Part number: IAG-ENG-S1020
• Case halves: Brand new OEM Subaru FA20F, converted to closed deck with CNC-machined inserts installed cryogenically
• Cooling: Coolant passages built into the closed deck inserts
• Pistons: IAG-Spec JE forged 2618 alloy, electroless nickel plated
• Connecting rods: IAG-Spec H-Beam forged with ARP 625+ rod bolts
• Crankshaft: New Subaru FA20
• Bearings: ACL or King race rod and main bearings
• Head sealing: Fire-Lock receiver groove machining; accepts 14mm head studs
• Compression ratio: 10:1
• Assembly: Hand-assembled in the USA, balanced and blueprinted; case and main bolts with factory sealant; installation instructions included

Before you order

Fire-Lock head gaskets and 14mm head studs are required and sold separately. Tuning is required for high boost and power levels, and IAG recommends professional installation. Verify that your 2015-2021 WRX has the FA20. Send us your VIN or engine code and we will confirm fitment before you order.

See also: FA20 vs EJ25 · head studs vs head bolts · is it worth replacing an engine? · signs of a blown head gasket · Subaru WRX and STI parts · FA20 vs FA24 · subaru fa20 / fa24 · IAG Performance Subaru blocks and all engines by engine code.

Shipping and returns

Shipping is a flat $80.00 per order to US addresses, and returns are free within 15 days of delivery. Questions before you order? Ask a parts specialist.