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Supertech Performance SEVN-1033D Black Nitrided Exhaust Valve Oversize - 1mm

(2001-2005 Subaru Outback)

Manufacturer

Picture for manufacturer Supertech Performance

Part Number

SEVN-1033D
8 reviews
Sale Price

$28.13

Estimated ship date Saturday, November 21

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Product Details

The Supertech Performance SEVN-1033D is a Black Nitrided +1mm Oversize Exhaust Valve engineered for high-performance and racing engine builds. Manufactured as a one-piece forged component, this exhaust valve delivers exceptional strength, sealing integrity, and long-term durability under extreme operating conditions.

Supertech exhaust valves are constructed from EV8 (21-4N) stainless steel and finished with a Black Nitride coating applied to the entire valve surface. This hardening treatment produces a smoother finish than chrome-coated stems, reducing friction between the valve stem and guide while achieving a minimum microhardness of 800HV. Unlike chrome coatings, the nitrided layer bonds at a microscopic level and will not flake or fracture under impact.

Key Features:

  • One-piece forged construction for superior strength and reliability
  • Black Nitride coating applied to the full valve for reduced stem-to-guide friction and extended service life
  • EV8 (21-4N) stainless steel alloy with application-specific heat treatment
  • +1mm oversize head diameter — requires aftermarket valve seats or machining of factory seats
  • Tip hardness exceeding 52 HRC for long-lasting durability
  • Manufactured dimensions: 31.50mm head diameter x 5.45mm stem diameter x 103.25mm overall length
  • Validated through ultrasonic testing, X-ray inspection, and Finite Element Analysis

The SEVN-1033D is sold per valve. Order the exact quantity needed to complete your engine build (e.g., order 12 for a full 12-valve engine).

Products specifications

Fits

2001-2005 Subaru Outback

Head Dia

31.50mm (+1.0)

Length

103.25mm

Material

Black Nitrided

Stem Dia

5.45mm

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