Manley Performance Subaru ExtremeDuty 33mm +1mm Oversized Exhaust Valve

Manley Performance Subaru ExtremeDuty 33mm +1mm Oversized Exhaust Valve


SKU: 11139-8 Category: Brand:

These valves are made from Inconel!

Manley Performance Sport Compact stainless steel valves utilize our exceptional “Race Series” alloy and are manufactured to the highest quality standards.  Manley valves are designed to outflow and outperform all others even in the most severe environments. Manley stainless valves feature gorgeous yet durable chrome stems, swirl polished under heads, fully hardened tips, completely machined combustion faces, closely controlled margin heights, and exact stem to seat concentricity to render a finished product that is unsurpassed.  Manley intake valves typically are built with our original “Pro-Flo” design which reduces the stem diameter in the fillet area for increased airflow but also less valve weight. In certain specific applications, Manley offers our “Extreme Duty” exhaust material.  Our “Extremealloy” alloy offers more hot hardness and high temperature strength than our competitors’ offerings.  This alloy is ideal for extremely high boosted applications where the exhaust gas temperatures reach what seem like unthinkable levels. Manley stainless valves are suitable for all applications ranging from the mild street performer to the jaw dropping 1000+ horsepower race cars competing at the drag strip or drifting events.

Note: Manley Performance strongly recommends that customers check their valve guide size in order to achieve the proper valve stem to guide clearance. Guides may need to be honed when replacing stock factory valves.

  • Part #: 11139-8
  • Type: Exhaust
  • Head Diameter: 33 mm
  • Stem Diameter: 5.96mm/.2345″
  • Installed Height: Stock
  • O/A Length: 104.75 mm
  • Tip Length: 3.5 mm
  • Underhead Angle/Radius: 25° x 11/32″
  • Margin: 060
  • Seat Width: .100
  • Top of Head: 20° Dish
Weight 3 lbs
Dimensions 12 x 12 x 6 in