Mahle MS BMW S65 B40 4.0L 92.00mm x 27.3mm CH 2.1cc 366g 10.1CR Pistons (Set of 8)

If you're rebuilding the engine in your BMW S65 B40 4.0L, Mahle's MS forged piston set is a solid choice for a high-performance build. These pistons are built from 4032 aluminum, a material known for its strength and resistance to thermal expansion, making them well-suited for demanding engine applications. Each piston measures 92.00mm in bore diameter and features a compression height of 27.3mm, designed to work with a 75.2mm stroke and 140.7mm connecting rod. The included 21mm wrist pins are also robust, ensuring reliable operation under high stress.

This set is engineered for a 10.1:1 compression ratio, which is a notable increase over stock and can contribute to improved power output when paired with appropriate tuning. Each piston weighs in at 366 grams, and the dish volume is 2.1cc, contributing to that specific compression ratio. Mahle is a well-known name in engine components, and this set reflects their commitment to producing durable, well-built parts for performance applications. They are designed to fit right into your S65 engine, simplifying the rebuild process.

When undertaking an engine rebuild of this caliber, it's important to ensure all components are properly balanced and installed according to manufacturer specifications. This set includes eight pistons, enough for a complete engine overhaul. Please note that these pistons are not CARB approved and cannot be shipped to California. Always refer to your engine builder's recommendations for assembly and break-in procedures.