Tom,
One of the benefits of a stronger spark is the ability to cross a
bigger gap. The fire across the bigger gap provides a greater area for
ignition of the mixture. Massive electrode spark plugs are of no great
benefit (Iridium aircraft fine wire plugs have very small electrodes) in that
the weak spark from a mag requires a small gap (.016 to .018) as opposed the
.032 gap (.028 to .036, depending) on the Iridium moped plug that I
use with the Lightspeed. Remember that massive electrode plugs had to be
gapped again after some use because of erosion of the electrode.
Another benefit of an Electronic Ignition is the ability to keep the
spark going thru maybe 20 or 30 degrees of crank rotation - This allows
for a higher probability of ignition of a non-ideal mixture sometime in
that span, even if the consequent event timing might suffer a bit.
Certain mags (starts with S and ends with K) are known to experience a
fair percentage of misfires at the plugs even though the observer
can't detect that happening.
No point in discussing another archaic device - mechanical points for
spark distribution.
One of the weaknesses of the LASAR system I once used was that the
aircraft plugs had to have the smaller gap, even when electronically fired,
because the backup was reversion to magnetos.
What is plug fouling - goop buildup that shorts the plug? Is that
easier to occur with tight gaps? Or, is it just because the weak
spark can't make the jump if the plug is not pristine? If the plug fires
every cycle, it should stay clean.
Yep, the systems are different. The results are not
misleading. Aircraft plugs foul more easily and bottom plugs have a
greater opportunity to become fouled.
Old Grayhawk
Perhaps you detect a bit of disdain for the systems widely used last
century.
In a message dated 5/1/2008 9:58:06 P.M. Central Daylight Time,
tom.gourley@verizon.net writes:
Doesn't Lightspeed use an automotive type plug instead of the massive
electrode plugs typically used with mags? I was just wondering if the
automotive plug is less prone to fouling. The Lightspeed probably does
fire through better, but unless the plug configuration is the same on the
Lightspeed and the mag it seems like the results could be a little
misleading.