The IAG Stage 2 Tuff short block starts with new Subaru 2.5L EJ25 engine case halves that are bored and honed to 99.75 on our in house Sunnen SV-10. IAG's in house honing process is able to set piston to wall clearances tighter for a quieter running engine. The short block is measured and assembled using a new 2012+ Subaru 2.5L heat-treated STI crankshaft that is matched to ACL or King race main bearings. Next Manley H-Tuff forged rods with ARP Rod Bolts are utilized to increase the power rating slightly at the expense of being heavier. The connecting rods are matched to ACL or King race rod bearings. The case halves are sealed with new OEM main case bolts and sealant. Finally Manley 99.75mm Platinum Series Forged Pistons are spec'd and installed finishing off the short block.
The IAG Stage 2 Tuff Short Block has a power output rating of 675BHP.
*All IAG short blocks are balanced and blueprinted.
Compression Ratio: 8.5:1 on D Cylinder Heads (EJ255)
Compression Ratio: 8.2:1 on B, V and W EJ257 Heads with standard thickness gasket.
Hardware / Seal Option:
Not planning on reusing your original short block service plugs and covers? IAG offers a simple comprehensive cover and seal kit that includes the (3) OEM wrist pin plugs, (3) OEM wrist pin plug washers, (1) OEM separator cover, (6) OEM separator cover bolts, (1) OEM wrist pin service cover, (1) OEM wrist pin service cover O-ring and (2) OEM wrist pin service cover screws. *If you are reusing your original wrist pin service plugs and covers always replace the (3) OEM wrist pin plug washers and (1) wrist pin service cover O-ring before installing a short block to avoid potential leaks.