Manley 03-06 Evo 8/9 (7 Bolt 4G63T) 85.5mm +0.5mm Over Bore 8.5:1 Dish Pistons w/ Rings

Manley Platinum Series Forged Piston Set — Mitsubishi 4G63 7-Bolt, 85.5mm, 9.0:1 (606005C-4)

A +0.5mm dished set at 9.0:1, built for a boosted 4G63 that's going to see real cylinder pressure. The -12cc dish is what keeps compression low enough to hold timing under high boost instead of pulling it to survive.

Forged from domestic 2618 alloy for strength and fatigue resistance under sustained load. Offset wrist pin design keeps start-ups quiet, and moly-coated skirts reduce friction and scuff risk. Pressure balance groove included, and the crown accommodates +1mm valve sizes if the head's been worked.

Manley's single-fixturing method turns the skirt and machines the ring grooves in one operation, which gives ring groove to skirt squareness a two-op process can't match. That's where ring seal and power come from. Exacting standards on ring lands and grooves, and cam and barrel skirt profiles that make power while staying gentle on cylinder walls.

Specs: 85.5mm bore (+0.5mm over), 1.375" compression height, -12.0cc dish, 22mm wrist pin, 341 grams. Sized for 88mm stroke with a 142mm rod. Replacement ring set is 46855-4.

Fitment: 7-bolt 4G63 — 1996-2006 Evolution IV through IX, 1992.5-1999 Eclipse GST/GSX, 1992.5-1998 Talon TSi, 1992.5-1994 Laser RS.

Set your clearance to spec — .0035" measured 1.100" from the bottom of the oil ring. 2618 grows with heat, and a tight bore is how these get scuffed on cold start.

Block work required — +0.5mm means boring and honing to size.

Set of 4 with premium steel top rings and Napier seconds from Total Seal, premium chrome moly wrist pins, and round wire locks. 9310 pin upgrade available.