For those who are interested, the electrons escape more easily from a
hot item than a cold one. The spark plug's center electrode is hotter
than the side electrode, so the spark is more easily initiated when
the center electrode is made negative with respect to the side
electrode. This is why automakers switched from positive ground to
negative -- igintion coil in a positive ground system generates a
positive pulse at the plug center electrode and the side electrode has
to emit the electrons. Vice-versa for the negative ground system.
Electrons also escape more easily from sharp edges than from rounded
ones, so that is why platinum is becoming popular (I believe -- if
anyone has other info, please contribute) -- it prevents erosion of
the edges of the center electrode, so it stays sharper longer.
Donald.
[SNIP]
> >
> >Steve :
> >
> >Connecting the coil backwards will result in a somewhat weaker spark,
> >although I can't recall why offhand (it has to do with the polarity of
> >the spark, reverse polarity doesn't work as well). It will not damage
> >the coil, or any other part of the ignition system.
> >
> >It's actually possible that your old coil was correctly connected, and
> >that the "Dist" and "Batt" terminals were marked for a positive ground
> >car (like a stock TR3).
[bandwidth preservation act invoked]
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