JE Pistons Subaru EJ257 Ultra Series 8.5:1 C/R 100mm Bore 83mm Stroke Piston Kit (Set of 4)

If you're building a high-horsepower Subaru EJ257 engine, especially one that will see significant boost, you need pistons that can handle the extreme cylinder pressures. These Ultra Series pistons from JE Pistons are designed specifically for that kind of demanding application. They are a well-built, fully featured option straight out of the box, ready to take on serious power.

What sets these pistons apart is JE's proprietary Aligned Grain Flow forging technology. This process maximizes the material's tensile strength, giving the pistons the toughness needed for high-boost environments. They also come with custom-level features like a thermal barrier crown coating, which helps reflect heat away from the piston crown and can improve exhaust scavenging. The skirts have a special coating to reduce friction and wear on both the piston and cylinder walls, which also helps quiet down the engine, especially during cold starts. Plus, they include lateral gas ports to help maintain a solid seal on the top compression ring, even at high RPMs and under heavy boost. These pistons are made 100% in the USA, and they come with high-strength wrist pins from Trend Performance, built for the rigors of performance engines.

This kit includes four pistons, each with a 100mm bore and a compression ratio of 8.5:1, which is a common choice for boosted EJ257 builds. Remember, these pistons are not CARB approved and cannot be shipped to California. For a robust EJ257 build designed for power, these JE Pistons are a solid option.