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Manley 11558-8 Race Flo NK-842 Stainless Steel Intake Valves

Manufacturer

Picture for manufacturer Manley

Part Number

11558-8
4 reviews
Sale Price

$188.69

4 left at this price

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Usually delivered within 2 days

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No Hassle Returns

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Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

Each valve is precision-manufactured from NK-842 stainless steel, a premium alloy that delivers superior fatigue strength and tensile resistance compared to standard EV-8 (21-4N) valves.

These valves feature the signature Pro Flo undercut stem profile — a 12-degree x 3/8 in. underhead angle that reduces shrouding and improves airflow into the combustion chamber. The stem is hard-coated with a .0002-inch thick chrome layer for long-lasting wear resistance, and each valve tip is hardened above the keeper grooves to resist rocker arm wear.

Key Specifications:

  • Valve Type: Intake
  • Head Diameter: 2.000 in.
  • Stem Diameter: .3415 in. (11/32)
  • Overall Length: 4.900 in.
  • Tip Length: .250 in.
  • Installed Height: Stock
  • Underhead Angle/Radius: 12 degrees x 3/8 in. (Pro Flo)
  • Margin: .050 in.
  • Seat Width: .080 in.
  • Top of Head: 7-degree dish
  • Weight: 109 grams per valve
  • Material: NK-842 stainless steel with chrome stem

Key Features:

  • NK-842 stainless steel construction for superior fatigue strength and heat resistance
  • Swirl-polished underhead area for optimized airflow and reduced turbulence
  • Fully machined combustion face for consistent sealing and performance
  • Hard-chrome stem (.0002 in. thick) resists wear far beyond standard flash-chrome treatments
  • Hardened valve tip prevents rocker arm wear at the tip contact surface
  • Pro Flo undercut stem design promotes increased flow velocity
  • Suitable for engines operating below 8,000 RPM

Manley Race Flo valves are the ideal upgrade for engines currently using EV-8 alloy valves, offering equivalent or greater tensile strength at a competitive price point. Note: Always measure existing valve head diameter and stem diameter before ordering to confirm fitment.

Products specifications

Approximate Weight (g)

114

Lock Groove Quantity

1-groove

Lock Groove Style

Conventional

Overall Valve Length (in)

4.940 in.

Overall Valve Length (mm)

125.476mm

Quantity

Sold as a set of 8.

Swirl Polished

Yes

Undercut Stem

Yes

Valve Head Diameter (in)

2.080 in.

Valve Head Diameter (mm)

52.832mm

Valve Head Style

7 degree dish

Valve Material

NK-840 stainless steel

Valve Stem Diameter (in)

0.341 in.

Valve Stem Diameter (mm)

8.661mm

Valve Tip Length (in)

0.290 in.

Valve Tip Length (mm)

7.366mm

Was fast to find the item that I was looking for.

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

This was an easy transaction, keep me notified thoughout the entire shipment. Price is what got my attention in the first place. I will be back for future needs.

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

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