MOTORTECH High Performance Spark Plugs

The expansion of MOTORTECH’s state-of-the-art ignition controllers is driven by the latest developments of modern spark ignited gas engines. The operation of these high performance engines with advanced compression rates and very efficient lean-burn combustion systems require much higher voltages to allow a perfect and effective combustion. MHP spark plugs are designed to meet the requirements, both of modern and common engine developments and reliably deliver highest voltages and thus a strong spark down into the combustion chamber. The J-type electrode design with IRIDIUM alloy discs on center and ground electrode provides reliable combustion and increased spark plug life and helps to reduce service costs due less spark plug changes.

  • Hot lock technology ensures increased spark plug durability even in high compression engines
  • J-type electrode design for enhanced combustion
  • Supplies even highest voltages of modern ignition systems like MOTORTECHʼs MIC series
  • Long design insulators for best flashover protection
  • Advanced spark erosion resistance
  • Suppression of electromagnetic interference (EMI)
  • Less spark plug changes reduce operation costs
  • Available with different thread sizes and reaches
    – M14x1.25
    – M18x1.5
    – 7/8-18 UNS
  1. Removable threaded brass SAE terminal
  2. Long aluminum oxide ceramic insulator offers best flashover protection, especially in combination with PolyMot™ spark plug leads and extensions
  3. Integrated stress resistant monolithic resistor suppresses electromagnetic interference (EMI)
  4. Unified hex size reduces amount of required service tools for installation
  5. J-type electrode design and use of higher erosion resistance materials ensure better combustion particularly on lean burn gas engines and longest service life
  6. Copper cored center electrode with laser welded IRIDIUM alloy disc
  7. Copper cored ground electrode with laser welded IRIDIUM alloy disc


  • Sales Flyer MHP-Plugs
    Sales Flyer MHP-Plugs  (1 MB)
  • Sales Flyer Spark Plug B4321
    Sales Flyer Spark Plug B4321  (584 KB)
  • Sales & Service Bulletin MHP-Plugs
    Sales & Service Bulletin MHP-Plugs  (120 KB)
  • Sales & Service Bulletin Spark Plug B4321
    Sales & Service Bulletin Spark Plug B4321  (194 KB)