Manley Performance Severe Duty Exhaust Valves 40,000 PSI Fatigue Tested

Manley Performance Severe Duty Exhaust Valves — 40,000 PSI Fatigue Tested Purpose-built for extreme duty , Manley Performance Severe Duty Exhaust Valves deliver unmatched durability and reliability for high-temperature gasoline engines. Engineered and tested to withstand the most demanding conditions, these valves set the industry standard for fatigue life and thermal performance. Key Features Proven fatigue strength: Tested at 40,000 psi and 1400°F , surviving up to 100,000,000 cycles —orders of magnitude longer than typical competitors. High-temperature materials: Exclusive XH-428 exhaust alloy with nearly double the ultimate tensile strength at 1500°F versus competitor EV-8. Precision intake material: NK-844 intake grade offers exceptional tensile strength at 1000°F—over four times better than competing intake materials. Durable construction: Chrome-plated stems and hardened tips resist wear and seat impact. Optimized combustion: Swirl-polished under-head areas and fully machined combustion faces improve airflow and combustion efficiency. Why Choose Manley Severe Duty Valves? When valves are subjected to seat bounce, applied stresses can spike from 20,000–25,000 lbs to 40,000–60,000 lbs. Manley’s Severe Duty valves are validated to survive these extremes, offering dramatically longer service life and reduced risk of failure in high-performance and racing applications. Upgrade your engine with valves designed for peak reliability, thermal stability, and optimized flow—trusted by builders who demand the best.