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NGK Racing Spark Plug R5671A-11


Shipping Cut-Off:  USPS 9:30am EST / UPS 1:00pm EST

NGK Racing spark plugs have been powering racing champions and can be found in every racing venue throughout the world. The center electrode of NGK Racing spark plugs has special configurations and designs to ensure durability and ignitability. These plugs bring ultra-high performance in a variety of heat ranges.


  • Designed for Racing: The conventional nickel alloy center electrode with a V-groove provides consistent performance.
  • Recommended Usage: Racing use only.
  • OE Ceramic Technology: High-grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance.
  • Solid Copper Core: The 98% pure copper core offers superior heat dissipation, conductivity, and ultra-wide heat ranges.
  • Cold-Rolled Threads: Prevents cross-threading and damage to cylinder heads.
  • Trivalent Metal Plating: Delivers superior anti-corrosion and anti-seizing properties, ensuring ease of installation and removal.


  • Plug Number: R5671A-11
  • Thread Size: M14
  • Heat Range: 11
  • Hex Size (in): 5/8 Inch
  • Preset Gap (in): 0.020 Inch
  • Thread Reach (in): 0.750 Inch
  • Number Of Ground Electrodes: 1
  • Center Electrode Core Material: Copper
  • Center Electrode Tip Material: Nickel
  • Approximate Resistor Value (Ohm): 1 Ohm
  • Insulator Height (mm): 50.5mm
  • Material Grade: Double Platinum
  • Service Number: R5671A-11