JE Pistons Honda K20A Ultra Series 86.25mm Bore 0.4 Dome Volume 10.1 Piston Kit (Set of 4 Pistons)

If you're building a high-horsepower Honda K20A engine, especially one intended for forced induction like turbocharging or supercharging, you need pistons that can handle extreme cylinder pressures. The JE Pistons Ultra Series are forged from 2618 aluminum and are designed from the ground up to meet those demands. These aren't just off-the-shelf pistons; they come with features typically found only in custom builds, making them a solid choice for serious engine work.

What sets these Ultra Series pistons apart is JE's proprietary Aligned Grain Flow forging technology. This process maximizes the material's tensile strength, which is crucial for resisting the immense forces generated in a high-boost environment. You also get a thermal barrier crown coating, a ceramic-based material that reflects heat back into the combustion chamber, helping to keep piston crown temperatures down. This not only aids in preventing detonation but also helps with exhaust gas scavenging. The pistons are also treated with a skirt coating to reduce friction and wear against the cylinder walls, which also helps quiet down the engine, especially during cold starts. Lateral gas ports are included to help maintain a strong seal on the top compression ring, even at high RPMs and under significant boost.

This kit includes four pistons, each with an 86.25mm bore and a dome volume that results in a 10.1:1 compression ratio. They also feature optimized pin oiling for enhanced lubrication of the wrist pin and bores, reducing heat and wear. All JE Pistons Ultra Series pistons are made 100% in the USA, including the high-strength, thick-wall wrist pins manufactured by Trend Performance. Please note that these pistons are not CARB approved and cannot be shipped to California.