CP Piston & Ring Set for Mini Cooper S N18 1.6L - Bore (77.0mm) - Size (STD) - CR (10.5:1)

When you're rebuilding the heart of your Mini Cooper S with the N18 1.6L engine, this CP Pistons Forged Piston & Ring Set (Part# SC7517-4) is what you get. Inside this box, you'll find a complete set of four forged pistons, each precisely machined to a standard 77.0mm bore. You also get the corresponding high-quality piston rings needed to properly seal the combustion chamber, along with wrist pins and locks to secure them. This set is engineered for a 10.5:1 compression ratio, a common target for performance builds that balance power with pump gas compatibility.

CP Pistons are well-known in the performance engine building community for their robust construction. These aren't cast pistons; they're forged from high-strength aluminum alloy, which makes them significantly more durable and resistant to the extreme pressures and temperatures found in a performance engine. This forging process creates a denser, stronger grain structure that can handle higher boost levels and more aggressive tuning than stock pistons. The pistons are also designed with specific skirt profiles and ring land depths to ensure proper oil control and ring seal, which is critical for engine longevity and performance. The standard bore size means these are a direct replacement for stock-sized cylinders, simplifying the machining process for your engine builder.

This set is a solid choice for anyone looking to build a reliable, high-performance engine for their Mini Cooper S. It's important to note that this part is not CARB approved and cannot be shipped to California. Always refer to your engine builder's specifications and the manufacturer's installation instructions for the most accurate guidance during your build.