Bill,
Ardun bill did a great job of explaining the meaning of the term,
"wasted spark". I wasn't aware of the motorcycle ignitions that used
this idea, I first became aware of this terminology with the
distributorless ignition systems on today's cars. One note, in the
tuneup profession we were always warned about reverse polarity. Not a
good thing since it takes about 20 % away from the ignition performance.
(It takes less voltage to move the current from the center electrode to
ground than from ground to center electrode because the current moves
more freely from hot to less hot.).
With the "wasted spark systems, one plug is correct polarity and the
other is reverse polarity since the current flows from the coil through
both plugs back to the coil. This does erode the center electrode on the
reverse polarity plug, and it does take more voltage to fire that plug,
but, it doesn't matter, these systems have the luxury of surplus voltage.
You are also right about current flow. According to Benjamin Franklin,
current flows from positive to negative (electrical theory) but in
really current flows from negative to positive (electron theory). This
said, still, when teaching Automotive Systems we still use the
electrical therory.
Tom, Redding CA - #216 D/GCC
Bill & Dee Bennett wrote:
> Ok somebody here explain to me what wasted spark is. I thought wasted spark
> meant that the plug fired an additional time during the exhaust stroke. It
> was explained to me by a manufacturer's rep (the large company cobbling up
> all the small high performance companies enuff said) today that wasted spark
> meant an additional spark but traveling in the wrong direction. He said
> normal spark direction was from the electrode to ground and that in wasted
> spark it travels ground to electrode and that was hard on the ignition
> system. I did not bother to waste my time with this uneducated person and
> thanked him and went on my way looking at the other manufacturers. For
> those that don't know I will explain hopefully without getting to technical.
> Regardless of what Benjamin Franklin and everyone else might have told you
> in a DC voltage system the voltage always flows from the Negative(-) side to
> the Positive(+) side. The spark plug electrode being positive charge has
> less electrons. The ground side of the plug has a negative charge(an
> abundance of electrons). The electrons are attracted to the positive side
> The path of voltage flow is always from the ground to the electrode. Ask me
> what this has to do with LSR and I would just shrug my shoulders cause like
> Glen waiting to hear how today turned out at Maxton.
>
> Bill
> Oh and by the way lightning does go from the ground up for the same reason.
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