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Manley Severe Duty Series Stainless Steel Valves 11865-8 Valves, Exhaust, Steel, 1.600 in. Diameter, .341 in. Stem, 5.121 in. Length, Chevy, Set of 8

SKU: MAN11865-8

Valves

Manley Severe Duty Series Stainless Steel Valves 11865-8 Valves, Exhaust, Steel, 1.600 in. Diameter, .341 in. Stem, 5.121 in. Length, Chevy, Set of 8

SKU: MAN11865-8

Valves
A$588.04
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: 2026-10-14 10:04:35

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
11865-8
Product Attributes - Part Type
Valves
Product Attributes - Product Line
Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC
807298054339
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.)
0.341 in.
Product Attributes - Exhaust Valve Stem Diameter (mm)
8.66mm
Product Attributes - Exhaust Overall Valve Length (in.)
5.121 in.
Product Attributes - Exhaust Overall Valve Length (mm)
130.073mm
Product Attributes - Undercut Stem
Yes
Product Attributes - Swirl-Polished
Yes
Product Attributes - Valve Tip Length (in.)
0.250 in.
Product Attributes - Valve Tip Length (mm)
6.350mm
Product Attributes - Valve Material
XH-428 stainless steel
Product Attributes - Approximate Weight (g)
105
Product Attributes - Valve Head Style
9 degree dish
Product Attributes - Valve Seat Width (in.)
0.100 in.
Product Attributes - Quantity
Sold as a set of 8.

Reference Information

Brand Name/s Manley Performance
StreetFX SKU man11865-8
SFX Item ID 4933580
Supplier Item Code 4933580
Manufacturer SKU 11865-8
Manufacturer UPC 807298054339

Compatibility

Application Data
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1962
    Ending Year1969
    Engine TypeV8
    Engine Size5.4L/327
    Engine FamilyChevy small block Gen I
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1967
    Ending Year1968
    Engine TypeV8
    Engine Size4.9L/302
    Engine FamilyChevy small block Gen I
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1967
    Ending Year2000
    Engine TypeV8
    Engine Size5.7L/350
    Engine FamilyChevy small block Gen I
    Valve Installed LengthStock
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1980
    Engine TypeV8
    Engine Size6.6L/400
    Engine FamilyChevy small block Gen I
    Valve Installed LengthStock

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