Manley 11684H-8 LS1 2.100" Hollow Stem Performance/Flo Intake Valve

The Manley 11684H-8 is a Performance/Flo (P/F) hollow stem intake valve engineered specifically for GM LS1 applications. Featuring a large 2.100-inch head diameter, this valve is designed to maximize airflow and improve volumetric efficiency in high-performance and racing LS1 builds.

Manley's hollow stem design reduces reciprocating valve train mass, allowing the engine to rev more freely and reducing wear on valve springs, retainers, and rocker arms under demanding conditions. The Performance/Flo profile features a back-cut design that promotes superior airflow past the valve seat compared to standard OEM-style valves.

Key Features:

• 2.100" head diameter for increased intake flow in LS1 cylinder heads
• Hollow stem construction reduces valve train mass for high-RPM durability
• Performance/Flo (P/F) design with back-cut for optimized airflow
• Manufactured from premium-grade stainless steel for heat and wear resistance
• Designed for GM LS1 cylinder head port dimensions
• Ideal for naturally aspirated, forced induction, and nitrous LS1 race engines

Manley Performance has been a trusted name in high-performance engine components for decades. The 11684H-8 intake valve set is a proven upgrade for serious LS1 engine builders looking to extract maximum power and reliability from their builds.