JE Pistons 99.52mm Forged Pistons (-25.50cc, 1.209 In. CH, 8.50:1 CR)
Brand New OEM Connecting Rods
Brand New OEM EJ257 Nitride Treated Crankshaft
King Rod and Main Bearings (Standard Size)
Brand New OEM Case Bolts, Seals, and Hardware
Brand New OEM Case Halves
Rated for 400bhp*
Professionally Measured Clearances
The Obsidian S1 (Stage 1) Subaru EJ255/EJ257 short block features stock bore forged JE pistons with all new components throughout the entire assembly. All bearing clearances and rotating assembly components have been professionally measured within acceptable factory specified tolerances. This is a great option for someone looking to make slightly higher than factory horsepower while still trying to stay within a budget. This block is a great option over the standard factory replacement short block because the common ring land failure issue has been eliminated by upgrading to forged pistons with a slightly larger piston-to-wall clearance and slightly larger ring end gaps.
*This rating is the maximum SAFE horsepower rating to the crankshaft. Quality in the tune, fuel, and installation has significant effects on the health of the engine as well as how much power it can safely/reliably produce.
