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Manley Severe Duty Series Stainless Steel Valves 12898-8 Valve, Intake, Steel, 2.250 in. Head Diameter, 5.594 in. Length, Chevy, Big Block, Each

SKU: MAN12898-8

Valves

Manley Severe Duty Series Stainless Steel Valves 12898-8 Valve, Intake, Steel, 2.250 in. Head Diameter, 5.594 in. Length, Chevy, Big Block, Each

SKU: MAN12898-8

Valves
A$618.16
Special Order. Contact for ETA. This item is out of stock in our warehouse and partner distribution centres. In some cases, this may be due to not having live inventory feeds available for all suppliers. Please contact us before ordering if you need to meet a specific deadline.
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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 Intake Valve

Data: v4.2 - Upd: 2026-10-14 10:11:07

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
12898-8
Product Attributes - Part Type
Valves
Product Attributes - Product Line
Manley Severe Duty Series Stainless Steel Valves
Product Attributes - UPC
807298018126
Product Attributes - Valve Position
Intake
Product Attributes - Intake Valve Head Diameter (in.)
2.250 in.
Product Attributes - Intake Valve Head Diameter (mm)
57.200mm
Product Attributes - Intake Valve Stem Diameter (in.)
0.311 in.
Product Attributes - Intake Valve Stem Diameter (mm)
7.90mm
Product Attributes - Intake Overall Valve Length (in.)
5.594 in.
Product Attributes - Intake Overall Valve Length (mm)
142.088mm
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
Stainless steel
Product Attributes - Lock Groove Quantity
1-groove
Product Attributes - Lock Groove Style
Beadlock
Product Attributes - Approximate Weight (g)
132
Product Attributes - Valve Head Style
5 degree dish
Product Attributes - Valve Seat Width (in.)
0.080 in.
Product Attributes - Quantity
Sold as a set of 8.

Reference Information

Brand Name/s Manley Performance
StreetFX SKU man12898-8
SFX Item ID 4928400
Supplier Item Code 4928400
Manufacturer SKU 12898-8
Manufacturer UPC 807298018126

Compatibility

Application Data
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1963
    Ending Year1969
    Engine TypeV8
    Engine Size7.0L/427
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1965
    Ending Year1970
    Engine TypeV8
    Engine Size6.5L/396
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year1972
    Engine TypeV8
    Engine Size6.6L/402
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration
  • Valve FitmentSearch by engine
    MakeCHEVROLET
    Beginning Year1970
    Ending Year2000
    Engine TypeV8
    Engine Size7.4L/454
    Engine FamilyChevy big block Mark IV
    Valve Installed Length0.350 in. over
    Cylinder Head TypeStock configuration

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