CP Ring ONLY for SC7021 Pistons CP Pistons CPPCPN-3327
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CP Ring ONLY for SC7021 Pistons

CP Pistons
CPPCPN-3327
Piston Rings
3 Units In Stock - Ships Next Business Day
$ 30.25
$ 30.25

SKU: CPN-3327

CP Ring Pack for SC7021 Pistons Subaru STI 2004-2021

CP CPN-3327 ring pack provides exact fit for SC7021 pistons in Subaru WRX STI EJ257 engines. Built for 2004-2021 models this set ensures reliable compression sealing during extreme boost and high RPM. Perfect for engine rebuilds that demand consistent power delivery and durability.

Key Features

  • Exact Piston Match: Sized for 99.75mm bore SC7021 pistons ensures zero gap issues and full face contact
  • Chrome Faced Top Ring: 1.2mm steel ring with chrome plating reduces friction and resists blow-by in turbo applications
  • Nitrided Second Ring: 1.5mm cast iron construction wears slowly maintains seal during high heat cycles
  • Flex-Vent Oil Ring: 2.8mm three-piece design controls oil effectively minimizes drag for freer revving
  • Pre-Honed Finish: Factory gaps set to Subaru specs 0.45-0.55mm top ring for quick break-in and long life

Product Notes

  • Rings only pistons SC7021 sold separately verify bore before install
  • Store in dry area avoid contamination prior to assembly
  • Compact packaging protects rings during transit

Installation Notes

  • Professional installation recommended.
  • Use CP-specific ring expander tools to avoid ring damage
  • Compatible with stock wrist pins and circlips from SC7021 kit

This Part Fits

Year Make Model Submodel
2004-2007 Subaru Impreza WRX STI
2008-2014 Subaru Impreza WRX STI
2015-2021 Subaru WRX STI
2015-2021 Subaru Impreza WRX STI

Why Choose CP-Carrillo?

  • Proven in NHRA Top Fuel and Pro Stock racing teams worldwide
  • Forged from 2618 T6 aluminum with advanced coatings
  • USA-made with tolerances held to 0.0002 inches

Frequently Asked Questions

  • Q: Will CPN-3327 fit 2017 STI EJ257?
    A: Yes matches all 2004-2021 EJ257 blocks with 99.75mm SC7021 pistons including sedan hatchback variants
  • Q: What ring materials are used?
    A: Top ring steel chrome faced second cast iron nitrided oil control flex-vent steel for balanced wear and sealing
  • Q: What warranty applies?
    A: CP-Carrillo offers limited lifetime warranty on rings against manufacturing defects when installed correctly

Shipping & Handling

  • Method: UPS Ground or USPS Priority
  • Availability: In stock - ships same or next business day
  • Packaging: Protective box 6 x 4 x 1 inches
  • Weight: 0.5 lbs

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