JE Pistons Ultra Series GM Gen V LT4 4.065in Bore/4in Stroke Set of 8 Pistons

If you're building a high-horsepower GM Gen V LT4 engine, especially one that will see boost or nitrous, you need pistons that can handle the extreme cylinder pressures. JE Pistons' Ultra Series are forged pistons designed specifically for these demanding applications. They incorporate advanced features typically found only in custom piston sets, all ready to go right out of the box.

What sets these Ultra Series pistons apart is JE's proprietary Aligned Grain Flow forging technology. This process maximizes the material's tensile strength, giving these pistons the toughness needed to withstand the intense forces inside a power-adder engine. You'll also find a thermal barrier crown coating, which is a ceramic-based material that reflects heat back into the combustion chamber. This helps keep piston crown temperatures down and can improve how efficiently exhaust gases are scavenged. To further reduce friction and wear on the piston skirts and cylinder walls, a special skirt coating is applied, which also helps quiet down the engine, especially during cold starts. These pistons are also equipped with lateral gas ports, designed to help maintain a strong seal for the top compression ring, even at high RPMs and under significant boost.

JE Pistons also includes high-strength, thick-wall wrist pins made by Trend Performance, ensuring they can handle the rigors of high-performance builds. The pin oiling has been optimized to keep the pin, bores, and small-end lubricated, reducing heat, friction, and wear. Every feature on these Ultra Series pistons is geared towards high-horsepower racing engines, and they are proudly made 100% in the USA. Please note that these pistons are not CARB approved and cannot be shipped to California.