JE Pistons Ultra Series GM Gen III/IV LS 4in Bore/3.622in Stroke Set of 8 Pistons

JE Pistons is well-known for making strong internal engine components, and their Ultra Series pistons are a prime example of that expertise. If you're building a GM Gen III or IV LS engine designed for serious power, especially with boost or nitrous, these pistons are engineered to handle the extreme cylinder pressures you'll encounter. They feature JE's proprietary Aligned Grain Flow forging technology, which is developed in-house to maximize the tensile strength of the aluminum, making them incredibly robust for high-performance applications.

Beyond their inherent strength, these Ultra Series pistons come equipped with features typically found only in custom builds. The thermal barrier crown coating is a ceramic-based material that reflects heat back into the combustion chamber, helping to lower piston crown temperatures and improve how efficiently exhaust gases are scavenged. You'll also find a skirt coating that works to reduce friction and wear on both the piston skirts and cylinder walls, which can also lead to quieter operation, particularly when the engine is cold. To ensure consistent lubrication under high stress, these pistons have optimized pin oiling features, and lateral gas ports are included to help maintain a solid ring seal even at high RPMs and under significant boost.

This set includes eight pistons, each with a 4.000-inch bore and designed for a 3.622-inch stroke. They are made from 2618 aluminum and feature a flat-top design with a -5.00cc dish. The included wrist pins are high-strength, thick-wall units from Trend Performance, built to withstand the demands of power-adder engines. Every component in this set is manufactured 100% in the USA, ensuring a well-built product for your demanding engine build. Please note that these pistons are not CARB approved and cannot be shipped to California.