LS1 R/M 1.590in Exhaust Valves

The MANLEY LS1 R/M 1.590-inch Exhaust Valves represent a purpose-built race series solution for LS-platform engine builders seeking maximum flow efficiency and durability under extreme combustion pressures. This set of eight stainless steel exhaust valves is engineered to handle sustained high-RPM operation, offering the metallurgical integrity and dimensional precision required in competition and high-performance applications.

Each valve measures 4.923 inches in length with a 0.314-inch valve stem diameter and a 1.590-inch head diameter—dimensions optimized for the LS engine family's cylinder head architecture. The stainless construction resists oxidation and thermal stress better than conventional steel, critical for exhaust valves that routinely experience temperatures exceeding 1,200°F in high-boost or naturally aspirated race engines. The race series designation confirms these valves meet the tighter tolerances and material standards demanded by engine builders who cannot afford reliability compromises.

This complete eight-valve set addresses the full exhaust valve requirement for LS1 cylinder heads in street performance, drag racing, and track applications. Buyers should verify head compatibility—LS1, LS2, LS3, and later variants may require different valve specifications. Installation should be performed by experienced engine builders familiar with proper valve seat work, clearance verification, and spring pressure adjustment to ensure correct seating and longevity.

MANLEY's reputation in precision engine components stems from decades of OEM and racing partnerships. Race series valves are selected by builders who prioritize flow characteristics and durability over cost, making them the standard for serious LS platform builds where performance and reliability are non-negotiable.