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Engines and Components› Pistons and Piston Rings

Carrillo

Piston Subaru EJ257 WRX STI 4 Cyl Bore (in) 3.917 Bore (mm) 99.5 Size STD Stroke 79

$287.25 $246.29 Save $40.96

SKU: C001 SC7420

In Stock
In Stock
Ships by Jun 14
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Description

The CP Pistons SC7420-4 is a forged aluminum piston and ring set designed for high-performance applications. It features a 99.5mm bore size and an 8.2:1 compression ratio, making it suitable for supercharged or turbocharged engines running on race gas, alcohol, or E85 fuels. The piston's construction includes a 1.2mm steel top ring and a 1.208" compression height.

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

BrandCarrillo
Part NumberC001 SC7420

Videos

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I Rebuilt My Subaru STI EJ257 Engine from Scratch!
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How do you file down Piston Rings? #shorts #short #shortvideo #shortsfeed #youtube #video #tricks
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Stock vs race pistons: Which is better?
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How to Install Unmarked Piston Rings
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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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