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NGK Racing Spark Plug R5671A-10


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

NGK Racing spark plugs are designed to withstand extreme use and grueling racing conditions. They have powered racing champions worldwide and are found in various racing venues.


  • Designed for racing: The conventional nickel alloy center electrode with a V-groove provides consistent performance.
  • OE Ceramic Technology: High-grade alumina silicate ceramic creates a stronger insulator for optimal dielectric performance.
  • Solid Copper Core: The 98 percent 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-10
  • Thread Size: M14
  • Heat Range: 10
  • Hex Size (in): 5/8 Inch
  • Center Electrode Material: Nickel
  • Preset Gap (in): 0.020 Inch (Preset Gap in millimeters: 0.50mm)
  • Thread Reach (in): 0.750 Inch (Thread Reach in millimeters: 19mm)
  • Resistor Plug: No
  • Ground Electrode Core Material: Nickel
  • Number Of Ground Electrodes: 1
  • Center Electrode Core Material: Copper
  • Center Electrode Tip Material: Nickel
  • Approximate Resistor Value (Ohm): 1 Ohm
  • Insulator Height (mm): 50mm
  • Electrical Terminal Type: Non-Removable Nut
  • Recommended Usage: Racing use only