## Namura NA-20005-4R Piston Rings 73.70mm - Reliability and Performance The Namura NA-20005-4R piston rings, with a diameter of 73.70mm, are a key component for optimal engine performance, efficiency, and longevity. Often overlooked, these rings play a fundamental role in the proper functioning of the piston. Namura, known for its high-quality motorcycle and scooter parts, designs its rings for specific applications, taking into account the type of cylinder sleeve, its coating, engine size, and stroke type (2 or 4). This allows for the selection of the ideal material composition to meet the demands of the operating environment. ### Key Features of Namura Piston Rings: * **Precise Manufacturing:** Namura NA-20005-4R piston rings are precisely manufactured, guaranteeing a tight seal and minimizing oil consumption. * **High-Quality Materials:** The use of durable materials, such as ductile cast iron or stainless steel alloy, ensures long life and wear resistance. * **Advanced Coatings:** Additional coatings, such as chrome, phosphate, and nitride, enhance corrosion and friction resistance, and improve sealing. * **Application-Specific Design:** The ring design considers the cylinder sleeve type, coating, engine size, and stroke, ensuring optimal fit and performance. ### Compression Rings: Made of highly ductile cast iron or stainless steel alloy, the compression rings exhibit excellent wear resistance and provide a gas-tight seal. Additional chrome, phosphate, or nitride coatings further enhance their durability and effectiveness. ### Oil Rings: These consist of three components: two scraper rails made of highly ductile cast iron or stainless steel alloy, also coated with chrome, nitride, or phosphate, and a single expander ring made of stainless steel. This design ensures efficient oil scraping and prevents oil from entering the combustion chamber. By choosing Namura NA-20005-4R piston rings, you are investing in the reliability and performance of your engine.