Manley Small Block Chevy 1.600in Head Dia Severe Duty Exhaust Valves (Set of 8)

SKU: MAN12337-8

Valves

MAN Severe Duty Valves...

Manley Performance

Manley Small Block Chevy 1.600in Head Dia Severe Duty Exhaust Valves (Set of 8)

SKU: MAN12337-8

Valves

MAN Severe Duty Valves...

LAST ONE! Est Ship 4-7 days. LAST ONE! This is the last unit at our distribution centre. Contact us if you need more. The ETA is the approximate time required to prepare your order for dispatch.

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Description

Manley Severe Duty® Valves deliver the ultimate in strength, reliability, and high-performance durability. Engineered for extreme gasoline engine temperatures, these valves are crafted from exclusive materials (XH-428 for exhaust and NK-844 for intake), offering unmatched tensile strength compared to competitive alloys. In fatigue testing at 40,000 psi and 1400°F, Manley exhaust valves endured 100 million cycles, while competitors failed after just 100,000, proving a 1,000× longer fatigue life. Each valve features chrome stems, hard tips, and swirl-polished underheads with fully machined combustion faces for superior airflow, efficiency, and wear resistance. Built for those who demand race-winning strength and precision, Manley Severe Duty® Valves set the industry standard for performance and endurance.

Part Type

Engine Exhaust Valve

Data: v4.2 - Upd: 2026-10-13 17:06:30

Features

Chrome stems and hard tips enhance durability
Exotic alloys for superior tensile strength, reliability, and longevity
Proven fatigue strength for extreme performance
Swirl polishing and machined faces improved airflow/optimized efficiency

Specifications

Product Attributes - Brand: Manley
Product Attributes - Manufacturer's Part Number: 12337-8
Product Attributes - Part Type: Valves
Product Attributes - Product Line: Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC: 807298081984
Product Attributes - Valve Position: Exhaust
Product Attributes - Exhaust Valve Head Diameter (in.): 1.600 in.
Product Attributes - Exhaust Valve Head Diameter (mm): 40.640mm
Product Attributes - Exhaust Valve Stem Diameter (in.): 0.314 in.
Product Attributes - Exhaust Valve Stem Diameter (mm): 7.97mm
Product Attributes - Exhaust Overall Valve Length (in.): 5.050 in.
Product Attributes - Exhaust Overall Valve Length (mm): 128.270mm
Product Attributes - Undercut Stem: Yes
Product Attributes - Swirl-Polished: Yes
Product Attributes - Valve Tip Length (in.): 0.260 in.
Product Attributes - Valve Tip Length (mm): 6.600mm
Product Attributes - Valve Material: Stainless steel
Product Attributes - Lock Groove Quantity: 1-groove
Product Attributes - Lock Groove Style: Conventional
Product Attributes - Valve Head Style: 18 degree dish
Product Attributes - Quantity: Sold as a set of 8.

Reference Information

Brand Name/s	Manley Performance
StreetFX SKU	man12337-8
SFX Item ID	4061730
Supplier Item Code	4061730
Manufacturer SKU	12337-8
Manufacturer UPC	N/A
Alternative References	1.600in