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Manley 11398-8 Race Series Stainless Steel LS1 Intake Valve Kit 2.080in

(1998-2002 Chevrolet Camaro; 1997-2004 Chevrolet Corvette; 2004 Pontiac GTO; 1998-2002 Pontiac Firebird; 2004-2005 Cadillac CTS)

Manufacturer

Picture for manufacturer Manley

Part Number

11398-8
5 reviews
Sale Price

$188.69

Estimated ship date Thursday, November 26

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Product Details

The Manley 11398-8 is a Race Series stainless steel intake valve kit designed for Chevrolet Gen III/IV Small Block LS engines including the LS1, LS2, and LS6. Built from Manley's premium NK-842 stainless steel alloy, these intake valves deliver the strength, durability, and precision airflow characteristics demanded by serious performance and race engine builders.

Each valve features Manley's signature Pro Flo underhead design — a 12° × 3/8" radius transition that reduces stem diameter in the fillet area to promote increased airflow while simultaneously reducing valve weight. The combustion face is machined to a 7° dish profile with closely controlled margin heights and exact stem-to-seat concentricity for consistent seating and combustion efficiency.

Key Specifications:

  • Valve Type: Intake
  • Head Diameter: 2.080 in.
  • Stem Diameter: 0.3133 in.
  • Overall Length: 4.874 in.
  • Tip Length: 0.175 in.
  • Underhead Angle/Radius: Pro Flo 12° × 3/8"
  • Margin: 0.050 in.
  • Seat Width: 0.095 in.
  • Top of Head: 7° Dish
  • Installed Height: Stock
  • Weight: 107 grams per valve
  • Valve Series: Race Series / Race Master
  • Material: NK-842 Stainless Steel

Construction Features:

  • Chrome stems for enhanced wear resistance and longevity
  • Fully hardened tips to withstand repeated valve train contact
  • Swirl polished underhead areas for optimized airflow
  • Fully machined combustion faces for combustion efficiency
  • Closely controlled margin heights for consistent performance

Manley's Race Series valves are engineered to perform across a wide range of applications — from spirited street builds to high-horsepower naturally aspirated and forced-induction race engines. With over 40 years of valve manufacturing experience, Manley has been a benchmark in the performance engine industry.

Note: Valve guides should be checked and correctly sized prior to installation to achieve proper stem clearances for the 0.3133" stem diameter.

Products specifications

Fits

1998-2002 Chevrolet Camaro; 1997-2004 Chevrolet Corvette; 2004 Pontiac GTO; 1998-2002 Pontiac Firebird; 2004-2005 Cadillac CTS

Approximate Weight (g)

107

Lock Groove Quantity

1-groove

Lock Groove Style

Conventional

Overall Valve Length (in)

4.874 in.

Overall Valve Length (mm)

123.8mm

Quantity

Sold as a set of 8.

Swirl Polished

Yes

Undercut Stem

Yes

Valve Head Diameter (in)

2.080 in.

Valve Head Diameter (mm)

52.8mm

Valve Head Style

7 degree dish

Valve Material

NK-842 stainless steel

Valve Seat Width (in)

0.095 in.

Valve Stem Diameter (in)

0.313 in.

Valve Stem Diameter (mm)

8.0mm

Valve Tip Length (in)

0.175 in.

Valve Tip Length (mm)

4.45mm

very pleased to have found you...easy to use website, and Super choices. I will be a repeat customer

Prices were good and the order shipped promptly. The email notice of shipment was a little late. It came after the order had arrived.

Product delivered as expected within 4 days. Lowest price on the web. No complaints.

It was fast and easy ;) I cant wait for my stuff to arrive

Nobody else had part in stock. Instant shipping and a good price. Will do business again!

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