Mahle MS Chevrolet SB 391cid 4.145in Bore 3.625 Stroke 6.125 Rod 1.062R CH 13.6CR Pistons Set of 8

If you're rebuilding a high-performance Chevrolet Small Block engine and aiming for serious power, a strong set of pistons is where you start. This Mahle MS piston set is built for those demanding builds, specifically designed for a 391 cubic inch displacement with a 4.145-inch bore. These aren't your average cast pistons; they're forged from 2618 aluminum, a material known for its exceptional strength and durability under high heat and pressure. This makes them ideal for applications where you're pushing the limits of your engine, whether it's for racing, serious street performance, or a custom build.

Mahle has engineered these pistons with a specific compression ratio of 13.6:1, which is quite high and typically paired with performance camshafts and cylinder heads to maximize power output. The 3.625-inch stroke and 6.125-inch connecting rod length are key dimensions that work together to achieve this displacement and compression. Each piston weighs in at 449 grams, a carefully managed weight that contributes to overall engine balance and performance. The 0.927-inch wrist pin diameter is standard for many performance applications, and the 1.062-inch radius dish helps achieve that high compression ratio. This set includes eight pistons, ready to be installed in your V8 engine.

Keep in mind that due to their high compression ratio and specific design, these pistons are not CARB approved and cannot be shipped to California. Always refer to your engine builder's specifications and the manufacturer's installation instructions to ensure proper fitment and performance for your specific application. This set is a solid foundation for a powerful, custom engine build.