JE Pistons Ultra Series GM Gen III/IV LS 4.005in Bore/4in Stroke Set of 8 Pistons

JE Pistons' Ultra Series pistons utilize a proprietary Aligned Grain Flow forging process, a unique method that maximizes tensile strength. This is crucial for handling the extreme cylinder pressures found in boosted or nitrous-fed V8 engines. These pistons are built to withstand the rigors of high-horsepower racing applications, ensuring reliability when you push your engine to its limits.

Beyond their robust forging, these Ultra Series pistons come equipped with custom-level features typically found only in bespoke builds. A thermal barrier crown coating helps reflect heat, keeping piston crown temperatures down and improving how exhaust gases are scavenged. The skirts are treated with a coating that reduces friction and wear on both the piston and cylinder walls, which also helps quiet down operation, especially during cold starts. Lateral gas ports are included to help maintain a strong ring seal, even under high RPM and significant boost conditions. These pistons are designed for a 4.005-inch bore and a 4-inch stroke, with a flat-top design and a -5.00cc dish, making them suitable for many GM Gen III and Gen IV LS engine builds.

Every component in this set, including the premium, thick-wall wrist pins manufactured by Trend Performance, is made 100% in the USA. This commitment to domestic manufacturing ensures a high level of quality control throughout the production process. Please note that these pistons are not CARB approved and cannot be shipped to California. If you're building a serious performance engine that demands the best in piston technology, this set is a solid option.