SEC: UNCLASSIFIED RE: Plasma Jet Ignitition

[Jensen, Adam]

Here in AUS they sell a device called Direct Hits, which is basically a
capacitor that attaches in between the spark plug and the spark plug wires.
They have been tested by a few magazines with varied results.  Slightly
improved performance from turboed motors and ones with modded efi systems
that can take advantage of the better burn.  They cost about $25 AUS each
here, but I don't have anymore info at hand. If anybody wants more info you
can email me and I will try to find out some contact details.

Adam Jensson

> -----Original Message-----
> From:	bearbvd at sni.net [SMTP:bearbvd at sni.net]
> Sent:	Thursday, 25 February 1999 6:27
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	Re: Plasma Jet Ignitition
> 
> >Hello,
> >
> >Just a thought.... why not add a small HV capacitor in parallel with a
> non
> >resistor plug (using  a low inductance path) and switch the ignition
> wires
> >to solid conductor types. When the normal ignition system fires the HV
> cap
> >would charge 'slowly' to the breakdown voltage of the gap and dump its
> >charge really quickly. The speed at which we could dump the charge
> through
> >the plug would not be limited by the inductance of the spark plug wires
> >or the leakage inductance of the ignition coils.
> >
> >Wen
> 
> I think I saw a web site a few months ago where somebody is selling plug
> mount capacitors--
> 
> Greg
> >
> >On Wed, 24 Feb 1999, Robert Harris wrote:
> >
> >> Why? -  All spark ignition starts with a plasma phase.  During this
> breakdown
> >> phase the "blast wave" created will exceed 10 to the 4th meters
> velocity at
> >> several hundred atmospheres pressure.   This injects a cloud of hyper
> >> temperature ~60,000k free radicals into the combustible mixture.  As
> the
> >> electrodes heat up and the conductance falls, the spark transitions
> into an
> >> arc, where the expanding velocity drops to below local sonic and the
> >> temperature falls to ~6000 k.   The energy transfer heat is primarily
> >> conduction to the combustible mixture.
> >>
> >> Increasing the size of the Plasma phase of ANY spark ignition results
> in
> >> greater quantity and penetration of free radicals into the combustible
> >> mixture.  The larger the cloud of free radicals expelled during the
> Plasma
> >> breakdown, the faster and surer the ignition.  Translation - less
> advance
> >> needed, faster flame front generation.  More power, more tolerance to
> the
> >> cyclic F/A variations - particularly those seen by the sparking device.
> >>
> >> There are literally hundreds of patents which I am patiently wading
> thru, but
> >> there has been a lot of thought on this.
> >>
> >> In a conventional ignition system, most of the energy is disapated in
> the arc
> >> and glow stage, yet the Plasma stage determines most of the ignition
> >> characteristics.  ANY design that pumps more energy into the plasma
> portion
> >> will increase the size of the cloud and result in better performance.
> And
> >> while the lab researchers try to reach 1 joule to virtually flood the
> main
> >> chamber and cause near instantaneous combustion ***** NOT DETONATION
> **** , I
> >> would be quite content to pump as much as practical into the plasma
> stage and
> >> suffer with only greatly extended mixture range, elimination of misfire
> and
> >> near TDC timing.
> >>
> >> How much is helpful?  Depending on the ignition design, only up to
> about 2 %
> >> of the total sparking energy is consumed in the Plasma phase.  Simply
> using
> >> another CD box triggered and rigged by a diode stack to fire into the
> first
> >> and modified to quickly dump its energy could potentially increase the
> plasma
> >> energy 50 fold if it could dump fast enough.
> >>
> >> >From the reading of the patents and others, simply shielding the spark
> in a
> >> pre chamber reduces the energy needed to fire an order of magnitude (
> why
> >> anti-fouler improve ignition )   Combining any small pre chamber with a
> >>pumped
> >> up plasma ignition should result in nice increase's in power and
> mixture
> >> range.  Also, the patents mention controls on when to plasma pump and
> >>when not
> >> to - just to reduce the electrical loss's to the system.  And yes,
> there is
> >> also discussion of reducing the resultant emi.
> >>
> >>
> >>
> >>
> >> 1963 Ford C-600 Prison Bus Conversion "Home"
> >> 1971 Lincoln Continental 460 "Christine"
> >> 1972 "Whale" Mustang awaiting transplant
> >> 1978 Dodge Long Bed Peeek Up "Bundymobile"
> >>
> >> Habaneros - not just for breakfast anymore
> >>
>