Manley Nissan (SR20DE/DET) 86.5mm +.5mm Oversized Bore 9.0:1 Dish Piston Set with Ring

Manley Platinum Series Forged Piston Set — Nissan SR20DE/DET 86.5mm, 9.0:1 Dish (638005C-4)

A +0.5mm dished set at 9.0:1, built for a boosted SR20 that's going to see real cylinder pressure. The -12cc dish is what keeps compression low enough to hold timing under boost instead of pulling it to survive.

Machined from high strength 2618 alloy forgings — lightweight yet robust enough to deliver long service life. Offset wrist pin design keeps start-ups quiet, and a pressure balance groove is included. Contour forgings provide the optimum balance between strength and weight with no grain-interrupting internal milling.

The finishing is where Manley earns it. A proprietary multi-step top ring groove machining process controls the groove's size, geometry, flatness, and finish. All final turning is performed in one fixturing, resulting in complete squareness of rings to the cylinder wall — that's where ring seal and power come from. Federal Form-Scan gauging validates skirt indexing to pinhole and skirt-to-skirt polarity.

Cam and barrel skirt profiles generate substantial power while staying gentle on cylinder walls.

Specs: 86.5mm bore (+0.5mm over), 1.260" compression height, -12cc dish. Chrome moly wrist pin with .150" wall, part number 42251.

Fitment: Nissan SR20DE and SR20DET — 1989-1998 240SX, 180SX, 200SX, Silvia S13/S14/S15, plus Sentra and Infiniti G20 applications.

Verify your compression before ordering. The final ratio depends on head gasket thickness and chamber volume — head work moves the number.

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

Round wire locks, tool steel wrist pins, and rings included at no extra charge. 9310 pin upgrade available.