Supertech High Performance Engine Valves, Springs, Valve Accessories, Pistons and Block Guards Viton Exhaust Valve Stem Seal 6mm for BMW 6mm Valve Stem Seal for Exhaust Valves / Viton for BMW B48 / B58 / N53 / N54 / N55 Supertech VSI-BM50-E Viton exhaust valve stem seals for 6mm intake valves. Application: Intake valves with 5mm valve stem Fits: BMW B48 / B58 / N53 / N54 / N55 engines Quantity: 1 piece The Viton valve stem seals for the exhaust side are specifically designed for BMW B48, B58, N53, N54, and N55 turbo engines, providing reliable oil control even under high RPM and boost conditions. Manufactured from high-temperature- and oil-resistant performance materials, they effectively prevent oil from entering the combustion chamber, reduce wear, and contribute to extended valvetrain service life. Ideal for high-performance street vehicles as well as motorsport applications. Designed for 5 mm valve stems .