JE Pistons BMW S65B40 10.5:1 Set of 8 Pistons

If you're rebuilding the engine in your BMW S65B40, especially for performance applications, a set of high-quality forged pistons is a critical component. JE Pistons has been a leader in this field for over 75 years, and this set is built specifically for your engine, offering a 10.5:1 compression ratio. They are engineered and machined entirely in the USA, using 2618 aluminum, which provides the strong tensile strength needed for demanding builds.

These pistons feature JE's proprietary Forged Side Relief (FSR) design, which helps minimize friction and reduce weight by using a narrower skirt and a shorter wrist pin. Depending on the specific application, they may also include an accumulator groove to help manage combustion gas pressure, improving ring seal and maintaining consistent power. Some applications also benefit from a skirt coating that further reduces friction and wear on the piston skirts and cylinder walls, while also helping to quiet down engine noise. This set includes high-quality wrist pins, locks, and JE Pro Seal premium piston rings, so you have the essential components for a proper installation.

This set is designed for a 3.622-inch bore and includes all eight pistons, along with the necessary pins and locks. Please note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for specific details regarding fitment and assembly.