King Engine Bearings BMW N55B30A Sputter Replacement (Size +0.25mm) Connecting Rod Bearing Set

If you're rebuilding the bottom end of your BMW N55B30A engine, getting the right connecting rod bearings is crucial for long-term health. These bearings from King Engine Bearings are designed as a sputter replacement, meaning they use an advanced overlay material that's built to handle the demands of modern engines. They come at a 0.25mm undersize, which is important if you're reconditioning your crankshaft journals to match.

King uses a unique three-layer material system with a steel backing for strength, a copper-lead alloy for heat dissipation, and a specialized sputter overlay that offers improved wear resistance and compatibility with various oil types. This combination helps ensure proper oil film formation and reduces friction, which is key to preventing premature wear, especially in performance applications or engines with higher mileage. The 0.25mm undersize is a common requirement when crankshaft journals have been machined to correct imperfections or to achieve a tighter clearance with new bearings.