Manley Performance

Fits 2004+ Subaru WRX STi with EJ257 Engine

Part #: 621002C-4

Overview

The Manley Platinum Series piston set is designed for high-performance Subaru WRX STi engines equipped with the EJ257 powerplant. Crafted from premium 2618 alloy forgings, these pistons are engineered to withstand the demands of aggressive tuning and spirited driving. Ideal for professional engine builders, tuners, and enthusiasts seeking durability, reliability, and enhanced performance, this piston set offers a significant upgrade over stock components. Whether you're building a high-horsepower build or seeking improved response and longevity, these pistons provide the foundation for a robust engine. Constructed with proven cam and barrel skirt profiles, the pistons promote optimal oil control and reduced friction. The moly skirt coatings on select part numbers further enhance wear resistance and thermal stability. Equipped with precision-machined tool steel wrist pins, these pistons ensure a secure fit and consistent performance under demanding conditions. Designed to support increased boost levels and power output, they are an excellent choice for those pushing their Subaru's capabilities.

Key Features

This piston set combines advanced materials and thoughtful design to deliver reliable performance and durability:

• Made from high-strength 2618 alloy forgings for superior toughness
• Optimized cam and barrel skirt profiles for improved oil control and reduced friction
• Tool steel wrist pins for enhanced strength and longevity
• Moly skirt coatings on select models for wear resistance and thermal stability
• 75mm bore with a +.25mm oversize for custom engine builds
• Designed for 99.75mm stroke configurations, supporting increased displacement
• 8.5:1 compression ratio for a balance of power and reliability

Construction & Design

The pistons feature a precision-machined design with high-quality alloy forgings, ensuring consistent weight and strength. The moly coatings on the skirts reduce friction and wear, contributing to engine longevity. The robust tool steel wrist pins are engineered for high-stress environments, providing secure attachment to the connecting rods and supporting high RPM operation.

Performance & Response

These pistons are engineered to support high-performance applications, helping your engine respond more efficiently under boost and load. Their durable construction ensures consistent compression and combustion stability, which translates to improved throttle response and power delivery. Designed to withstand elevated temperatures and pressures, they help maintain engine integrity during aggressive driving or tuning.

Installation & Fitment

This piston set is intended for use in Subaru WRX STi models with the EJ257 engine, specifically for builds requiring a 75mm bore and +.25mm oversize. Proper installation requires precise machining and assembly by qualified technicians familiar with high-performance engine builds.

What’s Included

The package includes a complete set of pistons with moly-coated skirts and tool steel wrist pins, ready for installation in compatible EJ257 engines. Additional hardware or components are not included and may be required for full engine assembly.