LS1 R/M 1.590in Exhaust Valves

The MANLEY LS1 R/M 1.590-inch Exhaust Valves are precision-engineered components designed for high-performance LS engine builds where reliability and flow efficiency matter. Built for LS1 platforms, these exhaust valves serve enthusiasts and professional builders tackling everything from street performance to track-focused applications.

When upgrading your valve train on a Gen III/IV LS engine, choosing quality over OEM components directly impacts throttle response, scavenging efficiency, and overall power delivery. The 1.590-inch head diameter on these exhaust valves balances flow area with structural durability under sustained high-RPM operation and aggressive cam profiles. MANLEY's manufacturing process yields strict tolerances on valve stem straightness and seat geometry, ensuring consistent sealing and minimal recession over extended use.

Builders upgrading cylinder heads on LS1 engines—whether for naturally aspirated high-RPM platforms or turbocharged/supercharged builds—rely on MANLEY exhaust valves to complete a reliable valve train package alongside upgraded springs, retainers, and keepers. The material composition and thermal properties allow these valves to resist valve-seat wear and maintain dimensional stability in the combustion chamber, making them ideal for high-performance applications.