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Manley Severe Duty® Series Chevy Small Block Intake Valve Kit – 2.080 in. Head Dia., 5.211 in. O/A Length, 0.3415 in. Stem

Your Price: $292.45

SKU: 11740-8

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Manley Valve – Intake, Valve-P/F 2.080,+.300.

Discover the pinnacle of performance and racing excellence with Manley’s Severe Duty® Valves. Exhaust valves crafted from XH-428 material and Intake valves from NK-844 material, these valves stand as a testament to our unwavering commitment to superiority in the industry. Severe Duty® Valves outshine the competition in every aspect.

  • Proven Fatigue Tests: The Severe Duty® Valves have undergone rigorous fatigue tests. In normal operation, valves experience 20,000 to 25,000 lbs of applied stress. When valves bounce on the seat, this stress soars to 40,000 to 60,000 lbs. Manley exhaust valves, tested at 40,000 psi and 1400°F, impressively endured up to 100,000,000 (one hundred million) cycles. In contrast, competitors’ offerings failed after just 100,000 cycles, showcasing a staggering 1000 times better fatigue life.
  • Designed for High Temperature Gasoline Engines: Engineered for superior performance in high-temperature gasoline engines.
  • Chrome Stems and Hard Tips: Incorporating chrome stems and hard tips for enhanced durability and longevity.
  • Optimized Combustion: Swirl polished under head areas and fully machined combustion faces for improved airflow and combustion efficiency.
  • XH-428 for Exhaust: No competitor worldwide offers the exceptional XH-428 as exhaust valve material. It boasts nearly double the ultimate tensile strength at 1500°F compared to the competition’s EV-8.
  • NK-844 for Intake: Our intake valve material, NK-844, is equally unmatched, displaying over four times the ultimate tensile strength of the competition’s best intake valve material at 1000°F.
SKU: 11740-8 Categories: , ,

GTIN: 00807298049229

Product Market


Head Diameter

2.080 IN

Stem Diameter

0.3415 IN

O/A Length

5.211 IN

Tip Length

0.250 IN

Margin Width

0.050 IN

Seat Width

0.080 IN

Top of Head

7 Degree Dish

Underhead Angle

Pro Flo: 12.00 DEG

Underhead Radius

3/8 IN

Valve Series

Severe Duty® Series

Valve Sub-Series

Pro Flo

Product Type

Engine Intake Valve Kit

Valve Quantity


Engine Detail – Web

Small Block

Instructions: Enter a value in the un-shaded boxes below as they pertain to your engine.
Note: For pistons BELOW the block @ TDC – value in box must be a POSITIVE number (.000)
Note: For pistons ABOVE the block @ TDC – value in box must be a NEGATIVE number (-.000)
Note: For a DISH piston – value in box must be a POSITIVE number (0.0)
Note: For a DOME piston – value in box must be a NEGATIVE number (-0.0)
Note: Manipulate the DOME/DISH & PISTON to DECK volumes to get the ratio you want.
Enter the number of cylinders of your engine
Finished bore of your engine
Stroke of your engines crankshaft
Rod Length
Ctr. to Ctr. length of your connecting rods
Gasket Bore
Head Gasket bore diameter
Comp. Gasket
Compressed Head Gasket thickness
Block Deck Height
Center of main bearing bore to top of block
Top Ring Down
Top of 1st ring to top of pistons(FLAT)
Chamber Volume
Cylinder Head chamber volume in CC’s
Dome/Dish Volume
DOME (-) or DISH (+) vol. (theoretical) in CC’s
Piston to Deck
Top of BLOCK to top of piston (FLAT) @ TDC
Click “Calculate” for dimension results.
Total Volume
Cylinder Volume
Total cylinder volume in CC’s =
Clearance Volume
All effective vol. above block deck @ TDC in CC’s =
Gasket Volume
Volume of your head gasket in CC’s =
Top Ring Volume
Total volume above the top ring @ TDC in CC’s =
Deck Volume
Volume of area above the pistons @ TDC in CC’s =
Piston Top Land
Piston top land diameter for volume calculations =
1/2 Stroke
1/2 stroke of your engine’s crankshaft in inches =
Compression Ht.
Ctr. of piston pin to top of piston (FLAT) in inches =
Cubic Inches
Cubic inch displacement of your engine =
For the given dimensions, your compression ratio