[DML] Re: Bolt On Performance (High Voltage Arc)
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[DML] Re: Bolt On Performance (High Voltage Arc)



When you start talking about points and the spark there you are
talking about a whole different subject. That spark is created because
of the points opening and the "inertia" (impedance) of the flow of
electrons trying to maintain the circuit. The condensor is supposed to
diminish the arc but can't eliminate it entirely and eventually the
points pit from the arc. The 10-12K spark on the older cars was in
large part limited by the cap, rotor, ignition wires, and radio
inerference. With better materiels and engineering the voltages have
gotten much higher. Not so much for a "bigger" spark but so as the gap
on the plugs wears and gets larger there is more than enough reserve
so you don't have to change the plugs so often. Instead of the 10,000
miles we used to change plugs you can get 100,000 miles now.
 The arc across the spark plug is nothing more than energy inputted
into the system of a compressed air-fuel charge. Once you reach the
threshold of the necessary energy to start the oxidation process any
additional energy (spark) is unneeded. More is always better but won't
contribute any further to the start of the oxidation process. The
extra is just reserve. 
BTW on open contact switchgear the shield things are known as arc
suppressors and you get the fire when you open the contacts. That arc
is very interesting. It is in fact a plasma of the air. Under the
right conditions even with the switch open the arc can conduct enough
electric to keep the circuit going! One reason why knife switches had
to come out of service!
David Teitelbaum
vin 10757  


--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@...> wrote:
>
> Forgot to mention points (in the 60's breakerless ignition hadn't been
> invented yet).
> 
> The higher the voltage, the greater the arc when it jumps through air.
> You should see railroad locomotive contacts when they close -- fire
> shoots straight out like a flame (a fireproof shield called an "arc
> chute" protects everything else in the electrical locker). In an
> automobile arcing from high voltage ignition will eat up a set of
> points. 10,000 volt ignition may also have been so prevalent to
> preserve them.
> 
> I of course run breakerless ignition. There's no penalty for arcing.
> In fact it's quite beneficial within my combustion chambers,
> especially since it's occuring 10 degrees BTDC (less time for the
> flame to spread). Note also that high voltage ignition works reliably
> no matter how cold or damp the air mixture is.
> 
> Regarding Bosch's "Blue Coil": In the 70's it was considered a racing
> coil. 18,000 volts was obviously pushing the performance envelope then
> (I wonder if owners of 10,000 volt systems at that time lambasted Blue
> Coil users for wasting snake oil money, as HEI users are so criticized
> today?). Performance bar has been raised since. The Blue Coil is
> positively pedestrian now, no hint of its performance heritage.
> 
> A useful analogy in this debate might be the internet connection I'm
> using right now. At one time my 56K (nee 33K) modem was state of the
> art. Then came broadband. As it was spreading, I remember telling
> people that my dialup connection still worked excellently and gave me
> all the performance I needed. There was no reason to upgrade.
> Broadband was wasted snake oil money in my mind. Then I tried it....
> 
> Bill Robertson
> #5939
> 
> >--- In dmcnews@xxxxxxxxxxxxxxx, "content22207" <brobertson@> wrote:
> >
> > Come on Martin, you know that you can't run aggressive ignition
> > (advance and plug gap as well as spark energy) on forced induction.
> > Even high compression gets dicey. MSD modules can compensate for turbo
> > boost, if I'm not mistaken.
> > 
> > Probably the only way manufacturers were able to get away with 10,000
> > volt ignition in the 1960's were 10:1 and 11:1 compression ratios that
> > prevailed. Timing was much closer to TDC as well. That may be one
> > reason GM pursued HEI in the 70's. Compression ratios dropped
> > precipitously, and spark moved closer to the bottom of the cylinder
> > for emissions. Basic engines didn't change a lick, however (every
> > domestic engine used in the 70's was a dumbed down 60's design, with
> > various bolt on emissions devices). I know my 1977-1979 Ford products
> > are much happier with high voltage ignition than the original coils (I
> > do retain the Duraspark modules). Everything changed radically in the
> > 80's, but HEI may have been a necessity in the 70's.
> > 
> > Bill Robertson
> > #5939
> > 
> > >--- In dmcnews@xxxxxxxxxxxxxxx, Martin Gutkowski <martin@> wrote:
> > >
> > > I can tell you that a stock original coil runs the spark quite
> happily 
> > > on #2727's Renault turbo engine at 1.2 bar of boost. A so-called 
> > > "performance" coil started misfiring at about 4psi...
> > > 
> > > Martin
> > >
> >
>




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