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Manley Severe Duty Series Stainless Steel Valves 12784-8 VALVE-S/D 2.300,+.200

SKU: MAN12784-8

Valves

Manley Severe Duty Series Stainless Steel Valves 12784-8 VALVE-S/D 2.300,+.200

SKU: MAN12784-8

Valves
A$615.99
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

Valve - Intake

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.

Additional Information

Manley Valve - Intake, Valve-S/D 2.300,+200

Part Type

Engine Intake Valve

Data: v4.2 - Upd: 2026-11-10 23:12:26

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

Data: v2 - Desc: v4.2 - Upd: 2026-11-08 05:30:36

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Manley Performance, Manley
StreetFX SKU man12784-8
SFX Item ID 4931430
Accounting SKU man-12784-8
Manufacturer SKU 12784-8
Manufacturer UPC 807298050560
Alternative References 12784-8, MAN-12784-8

VALVE-S/D 2.300,+.200

Manley Severe Duty series performance valves are a great choice for your high performance or race engine. All valves are made from stainless steel (intakes are NK-844; exhausts are XH-428) with chrome stems and hardened valve tips. Severe Duty series valves are made of superior materials, are fully machined and swirl polished, and are available with either undercut "Pro Flo" stems or straight stems.

Product Attributes
BrandManley
Manufacturer's Part Number12784-8
Part TypeValves
Product LineManley Severe Duty Series Stainless Steel Valves
UPC807298050560
Valve PositionIntake
Intake Valve Head Diameter (in.)2.300 in.
Intake Valve Head Diameter (mm)58.420mm
Intake Valve Stem Diameter (in.)0.311 in.
Intake Valve Stem Diameter (mm)7.90mm
Intake Overall Valve Length (in.)5.444 in.
Intake Overall Valve Length (mm)138.278mm
Undercut StemNo
Swirl-PolishedYes
Valve Tip Length (in.)0.250 in.
Valve Tip Length (mm)6.350mm
Valve MaterialStainless steel
Lock Groove Quantity1-groove
Lock Groove StyleBeadlock
Approximate Weight (g)129
Valve Head Style5 degree dish
Valve Seat Width (in.)0.080 in.
QuantitySold as a set of 8.
NotesUnder head angle/radius 10 x 3/8 in. Valves are 0.200 in. longer than stock height. Beadlock valve locks are required.

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