Small Block Chevrolet Severe Duty Exhaust Valves - Set of 8 by Manley Performance
The Severe Duty series of valves is the Manley signature in the performance and racing industry. Exhaust material XH-428 and intake material NK-844 is offered by no competitor in the world. And no pair of materials show such clear dominance over all others. Ultimate tensile strength of XH-428 at 1500F is nearly double the competitors EV-8. At 1000F the Manley NK-844 displays more than four times the ultimate tensile of the competitions best intake material.
In addition to the vastly superior strength and fatigue characteristics of Manley NK-844, our exclusive intake material exhibits an uncanny ability to resist chordal fractures. In an excellent sealing combustion chamber, the intake valve is actually deformed by the fuel explosion and pushed up into the port. The effect of this continuous deformation on competitors material eventually is a chordal fracture propagating from the circumference of the valve and quickly becoming a missing pie-shaped piece. Manley NK-844 is the absolute best choice of material to combat disastrous chordal fractures.
Further proof of the superiority of the Manley Severe Duty valves is evident in our comprehensive fatigue tests. In normal operation where valve float is non-existent, a valve will experience 20,000 to 25,000 lbs of applied stress. However, when valves bounce on the seat the stress immediately soars to 40,000 to 60,000 lbs. Manley exhaust valves (at 40,000 psi and 1400F) ran to 100,000,000 (one hundred million) cycles while competitors offerings failed at 100,000 cycles. Thats 1000 times better fatigue life.
Features
- Head Diameter: 1.600"
- Stem Diameter: .3415"
- Installed Height: .200 Longer
- O/A Length: 5.165"
- Tip Length: .290"
- Underhead Angle/Radius: 15 x 1/2
- Margin: .090"
- Seat Width: .100"
- Top of Head: 9 Dish
- XH-428 Stainless Material
- Chrome Stems and Hard Tips
- Swirl Polished and Fully Machined
Benefits
- Superior Stainless for High Temperature Gasoline Engines
- Exhaust Material XH-428 with Double the Ultimate Tensile Strength (at 1500F) over the competition
Please Note: The image provided is generic and may not be an accurate representation of the product you will receive
Applications
- 2004-2007 Cadillac CTS V
- 2007-2008 Cadillac Escalade Base
- 2007-2008 Cadillac Escalade ESV Base
- 2008 Cadillac Escalade ESV Platinum
- 2007-2008 Cadillac Escalade EXT Base
- 1998-2002 Chevrolet Camaro Z28
- 1997-2008 Chevrolet Corvette Base
- 2001-2004 Chevrolet Corvette Z06
- 2005-2006 Chevrolet SSR Base
- 2006-2008 Chevrolet Trailblazer SS
- 2007-2008 GMC Yukon Denali
- 2007-2008 GMC Yukon XL 1500 Denali
- 2008 Hummer H2 Base
- 1998-2002 Pontiac Firebird Formula
- 2004-2006 Pontiac GTO Base
What's In The Box?
Warranty
- Manley products, due to their intended use, are sold without warranty.
