Manley 11104-8 BBC Intake SS Severe Duty Valve 34 mm

Price:   $165.20

Manley 11104-8 BBC Intake SS Severe Duty Valve 11-32 Stem 34 mm Head Dia. x 6 mm / .2362” Stem Dia. Installed Height

Type: Intake
Head Dia.: 34 mm
Stem Dia.: 6 mm / .2362”
Installed Height:
Length: 101.35 mm
Tip Length: 3.5 mm
Underhead Angle/Radius: Pro Flo: 22° x 5/16"
Margin: .050"
Seat Width: .075"
Top of Head: 17° Dish

XH-426 Stainless Exhaust Material
NK-842 Stainless Intake Material
Chrome Stems and Hard Tips
Swirl Polished and Fully Machined
Improved flow with “Pro Flo” Intakes

MAZDA MIATA 1.8L - DOHC 16 VALVE ( BP056 ) - 1990 - 1999

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 and demonstratable dominance over all others. Ultimate tensile strength of XH-428 at 1500°F is nearly double the competitor's EV-8. At 1000°F the Manley NK-844 displays more than four times the ultimate tensile of the competition’s 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 nonexistent,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 1400°F ) ran to100,000,000 ( one hundred million ) cycles while competitors failed at 100,000 cycles. That’s 1000 times better fatigue life.

Manley Performance is universally acknowledged as the leading manufacturer of performance and racing valves in the world.

The reason for Manley’s overwhelming success is simple: QUALITY. We offer the best materials in the industry - exclusive materials our competitors do not possess. Our stems are hard coated with .0002" thick chrome rather than a few millionths of flash. Our hard tips are superior to competitors’ puddled stellite which can crack and erode off the stem. Our valve head and under head shapes have been in the forefront of the quest for improved flow since the late 1960’s. And always each Manley valve has been price targeted to specific markets to ensure the best possible value to the customer.

Set of 8 Valves



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  • Model: 11104-8
  • Shipping Weight: 2lbs
  • 3 Units in Stock
  • Manufactured by: Manley




This product was added to our catalog on Tuesday 19 April, 2011.