{"product_id":"manley-performance-04-12-impreza-wrx-sti-ej257-platinum-series-piston-set-with-rings-99-75-mm-bore-9-8-1-compression","title":"Manley Performance [04-12 Impreza WRX STI] EJ257 Platinum Series Piston Set with Rings - 99.75 mm Bore, 9.8:1 Compression","description":"\u003cp\u003eManley's signature Platinum Series pistons deliver forged strength for Subaru EJ257 2.5L turbo engines — 2006-2014 WRX and 2004-2012 WRX STI. Machined from high-strength 2618 alloy forgings with an offset wrist-pin design for quiet start-ups, these 99.75mm (+0.25mm overbore) dished pistons run the stock 79mm stroke with 9.8:1 compression for high-horsepower, high-boost builds. Every kit includes moly-coated skirts, premium chrome moly wrist pins, round wire locks, and premium steel top rings with Napier second rings and higher-tension oil rings from Total Seal.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003ePart number: 612102C-4 — set of 4 pistons, wrist pins, ring sets, and round wire locks\u003c\/li\u003e\n\u003cli\u003eBore 99.75mm (+0.25mm overbore); -10cc dish; 51cc cylinder head; 9.8:1 compression\u003c\/li\u003e\n\u003cli\u003eStock 79mm stroke, 5.137\" rod length, 1.209\" compression distance; 423 grams each\u003c\/li\u003e\n\u003cli\u003eMachined from high-strength 2618 alloy forgings with cam and barrel skirt profiles\u003c\/li\u003e\n\u003cli\u003eMoly-coated skirts and pressure balance groove reduce friction and improve ring seal\u003c\/li\u003e\n\u003cli\u003eIncludes Total Seal ring set 46997DT-4, premium chrome moly wrist pins, and round wire locks\u003c\/li\u003e\n\u003cli\u003eAccommodates +1mm valve sizes; recommended piston-to-wall clearance .003\" (mild boost) \/ .0035\" (high boost)\u003c\/li\u003e\n\u003cli\u003eProfessional installation required — cylinders must be bored and honed to 99.75mm\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Manley Performance","offers":[{"title":"Default Title","offer_id":47258140606566,"sku":"man612102C-4","price":741.18,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0075\/8703\/7237\/files\/group-6fb279de-3abc-410e-9607-f540300bf0a1-800_913204cd-1148-4766-9028-fa3f76feaef2.jpg?v=1790174965","url":"https:\/\/jdmuscleusa.com\/products\/manley-performance-04-12-impreza-wrx-sti-ej257-platinum-series-piston-set-with-rings-99-75-mm-bore-9-8-1-compression","provider":"JDMuscle","version":"1.0","type":"link"}