Tuesday, March 01, 2016

here's a spark plug design with the wrong idea in the design on the ground electrode

But it's the only one I've seen with a twin design


  1. Jesse, I have a set of these in my 29 Ford now for easily 10 years and they work great. I've got a small plug collection in my home office with one of them in it and even carry a couple of spares in the car. I actually used them because they're pretty, but any time I've pilled them,, they're burning clean.

    1. well that's good news, but don't you agree that shrouding the spark makes for less flame to start combustion? And if that design was more effective that the single or quad ground, it would still be used? It has to be decently useful or this Hudson wouldn't have won the race. Tempest Aviation spark plugs have dual grounds, but they are running up along the anode. NGK racing plugs have none

    2. at least I said wrong, and not worst idea

  2. Generally, you're right that it's best to have less material in the way of the developing flame. The electrodes will absorb the heat from the flame and slow down the burn.
    I expect that on a 1953 Hudson or 1929 Ford, it's not as big of an issue as on modern engines. The engines of that era were probably over-rich and had less spark advance, and nobody could measure the ignitability or idle stability that would show the difference.
    Just like today, someone is trying to sell spark plugs with features that they claim make them work better - less fouling, easier starting, smoother idling, saves gas. See SplitFire, E3, Bosch +4, etc.