Engines and Components› Pistons and Piston Rings

CP Pistons

CP Piston & Ring Set for Subaru EJ257 WRX STi - Bore (100.5mm) - Size (+1.0mm) - CR (8.2) - Single

$246.29

SKU: C00A SC7423-1

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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Description

The CP Pistons SC7423 is a set of forged pistons designed for Subaru EJ255 and EJ257 engines. These pistons feature a bore size of 100.5mm with a +1.0mm oversize and a compression ratio of 8.2:1. They are balanced to within 1 gram and include wrist pins and pin fitting at no additional cost.

Constructed with dedicated forgings and fully CNC machined in the USA, these pistons are built for durability. They incorporate accumulator grooves, dual forced pin oilers, and pick lock grooves.

Fitment

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

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Specifications

BrandCP Pistons
Part NumberC00A SC7423-1

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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