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Manley Severe Duty Series Stainless Steel Valves 11847-8 Valves, Exhaust, XH-428 Stainless, 1.900 in. Diameter, 5.522 in. Length, Chevy, Big Block, Set of 8

SKU: MAN11847-8

Valves

Manley Severe Duty Series Stainless Steel Valves 11847-8 Valves, Exhaust, XH-428 Stainless, 1.900 in. Diameter, 5.522 in. Length, Chevy, Big Block, Set of 8

SKU: MAN11847-8

Valves
A$589.63
Available from MFR. This item is available from the manufacturer's distribution centre. The dispatch timeframe shown is an estimate based on historical order processing and release times for this part. This item is not held in our own warehouse, and actual dispatch timing may vary depending on manufacturer workload and logistics at the time of ordering.
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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 10:12:08

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
11847-8
Product Attributes - Part Type
Valves
Product Attributes - Product Line
Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC
807298053943
Product Attributes - Valve Position
Exhaust
Product Attributes - Exhaust Valve Head Diameter (in.)
1.900 in.
Product Attributes - Exhaust Valve Head Diameter (mm)
48.260mm
Product Attributes - Exhaust Valve Stem Diameter (in.)
0.342 in.
Product Attributes - Exhaust Valve Stem Diameter (mm)
8.69mm
Product Attributes - Exhaust Overall Valve Length (in.)
5.522 in.
Product Attributes - Exhaust Overall Valve Length (mm)
140.258mm
Product Attributes - Undercut Stem
No
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 - Lock Groove Quantity
1-groove
Product Attributes - Lock Groove Style
Conventional
Product Attributes - Approximate Weight (g)
132
Product Attributes - Valve Head Style
20 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 man11847-8
SFX Item ID 4927354
Supplier Item Code 4927354
Manufacturer SKU 11847-8
Manufacturer UPC 807298053943
Alternative References XH-428

Compatibility

Application Data
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1965
    Ending Year1970
    Engine TypeV8
    Engine Size6.5L/396
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.100 in. over
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1966
    Ending Year1969
    Engine TypeV8
    Engine Size7.0L/427
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.100 in. over
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1972
    Engine TypeV8
    Engine Size6.6L/402
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.100 in. over
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1990
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.100 in. over
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1991
    Ending Year1995
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen V
    Valve Installed Length0.100 in. over
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1996
    Ending Year2000
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Gen VI
    Valve Installed Length0.100 in. over

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