Manley 632400C-4 Turbo Tuff Forged Piston Set 99.50mm Bore Subaru EJ257 2.5L

Featuring a 99.50mm bore diameter and a 1.130-inch compression height with a dish crown design, these pistons are engineered for high-output, boosted applications where strength and reliability are critical.

Manley's Turbo Tuff Series pistons are forged from domestic 2618 high-strength alloy, the preferred material for forced-induction and race engines due to its superior ductility and fatigue resistance under extreme heat and pressure. A moly-coated skirt reduces friction and wear during break-in and throughout the life of the engine, while the pressure balance groove helps manage combustion blowby for improved ring seal.

Key Features:

• 2618 alloy forging — domestic high-strength material for superior durability under boost
• 99.50mm bore diameter with dish crown design
• 1.130-inch compression height
• Moly-coated skirts for reduced friction and extended engine life
• Pressure balance groove for enhanced ring seal and combustion efficiency
• Offset wrist pin design for quiet start-ups and reduced piston slap
• Cam and barrel skirt profiles for maximum power with minimal cylinder wall wear
• Exacting ring lands and grooves machined to strict tolerances for optimal ring seal
• Premium Chrome Moly wrist pins included; 9310 alloy Turbo Tuff/DLC upgrades available
• Unique single-operation fixturing ensures perfect ring groove-to-skirt squareness

Manley Performance has been a trusted name in professional engine building since 1966, supplying OEM-grade components to racers, tuners, and engine builders worldwide. The 632400C-4 piston set is the ideal foundation for a high-performance EJ257 engine build.