Both EJ 207 (first seen in 1999) and EJ257 (first seen in 2004) are semi-closed deck.
EJ207 has forged piston with STI heads, STI conecting rods, special crankshaft with tuftride impregnation to case-harden its bearing surfaces.
EJ257 uses hypereutectic aluuminum alloy pistons (not forged). AVCS for timing optimized that yield power and torque at all time. Special connecting rods made from high-carbon steel.
EJ257 is more advance for high-power applications.
