Originally posted by Axis Power Racing
It's a cast hypereutectic piston. I took it to CP and had them check it out and that's what they told me. They couldn't tell if it was hyper or just plain cast but it's def. not forged.
Block looks nice and sturdy, but the steel liner for the cylinder is exceptionally thin compared to other subaru engines. The 2.2t block has a fairly thick steel liner in it.
Rods actually look less beefier than the 2.5rs rods, but have bolts instead of studs and also have locating pins on both sides of the cap. These help A LOT. Crank looks like bone stock 2.5rs, but with slightly better counterweights and edging. There is no double oiling holes like on all 2.0 sti motors.
All oiling and water passages look similar to other ej series motors.
Well I guess that kills the piston debate....
Thanks for the info and the tear down pics.