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Copper Core Spark Plugs


  • ACCEL C-Cut Copper Spark Plugs creates a considerably hotter spark that lets the flame expand more rapidly in the combustion chamber
  • Allows spark to expand directly above the midpoint of the electrode core – preventing the spark from being shrouded by the ground strap.
  • Gives the flame an unblocked area to grow – creates a larger flame front for a more complete burn.
  • Reduces excess heat absorption of the electrode and ground strap, also known as the “quenching effect”, which leads to misfiring, rough idle and overall poor performance.
  • Produces a larger spark nucleus without having to increase the spark gap.
  • Creates a more complete burn of the air-fuel mixture resulting in -Increased performance, improved throttle response, greater fuel efficiency and reduced emissions.

ACCEL has improved the ignitability of the spark plug in a new design! ACCEL has always utilized unique electrode grounding designs to improve combustion and create a larger spark.


  • The Copper core is a better conductor than Iridium or Platinum plugs
  • Creates a considerably hotter spark that lets the flame expand more rapidly in the combustion chamber
  • Provides a more complete and efficient burn of the air/fuel mixture
  • Copper dissipates heat much better than other materials
  • Instant throttle response
  • Reduced fouling and misfire
  • Minimized flame dissipation
  • Machine-rolled threads protect your valuable cylinder heads
  • Whether using on the street or on the strip, ACCEL HP Copper Core spark plugs deliver!

Shorty Spark Plugs For Tubular Exhaust Headers.

Compare The Facts

Heat Range:

The term “spark plug heat range” can be misleading. Many think that it has something to do with a hotter spark and it does NOT. The heat range of a spark plug is its ability to transfer heat from the combustion chamber to the cylinder head. The heat transfer pulls heat out of the combustion chamber and at the same time away from the spark plug tip. This is most commonly done by changing the contact area of the porcelain insulator nose to the shell during manufacturing. A visual comparison of the two extremes make this very clear, looking at the colder plug you can see where the porcelain meets the shell and on the hotter plug the point where the porcelain meets the shell is further down inside. As a general rule of thumb use the coldest plug possible without fouling at low speed or idle. The use of too hot a plug may cause severe engine damage. The guideline for the difference in tip temperature from each heat range to the next is 70°C (158°F) to 100°C (212°F).

Spark Plugs Diagram Image

Considerations in choosing the heat ranges:

If an engine is normally operated at low speeds or at low temperatures then, a hotter heat range may be required to keep the spark plug from fouling. If the engine is modified, operates at high RPM, under heavy loads or at high temperatures then, a colder heat range spark plug will be necessary to help prevent detonating or preigniting. All engine modifications which increase cylinder pressure typically increase combustion temperatures, and therefore, increasing these temperatures will require a colder heat range. So, if you think you need a higher octane fuel to keep the engine from pinging, you will probably need a colder plug as well. It is important to follow the cylinder head manufacturers recommended torque specification for the spark plugs. It is also a good practice to put a small amount of anti-seize compound on the treads, but be sure that this does NOT insulate the spark plug from the cylinder head.

Spark Plugs Diagram Image

Tech & Support

  • In Stock
  • Year
  • Make
  • Model
  • Clear
  • Filter
Heat Range
  • 1 Step Colder
  • 2 Steps Colder
  • 4
  • 6
  • 7
  • Stock
  • Shorty
  • Standard
  • 1
  • 4
  • 6
  • 8
  • .375"
  • .460"
  • .708"
  • .750"
  • .8125"
  • 1"
  • 1.04"
Thread Size
  • 12mm
  • 14mm
  • 16mm
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    Copper Core Spark Plugs

    ACCEL HP Spark Plugs are made with a Copper core which is a better conductor than Platinum and Iridium. They deliver a stronger spark especially in high performance applications where high combustion pressures are present. Copper is much better at dissipating heat than other materials which lessens the chance of a misfire.