Spark plugs/injectors

[Joachim M. Wagner]

Hi, Danny!

There are already some direct petrol engines on the market!!!!

Mitsubishi was the first one! The have the GDI-Engine ready, it's sold even
here in Germany at least for 6 - 7 months now!

And the other thing is: lean mixtures can be burnt very good, but not with
an "unformatted" or unspecified energy which is used for ignition. The
ignition energy must have the correct phase/magnitude-ratio to burn really
the fuel! And then also the NOx - problem can be reduced greatly. There is
a impulse oscillator ignition 
system on the market here in Germany which can do both of it perfectly.

If you need such a system, give me the type of car and I can probably
arrange for you. ( I think price was around 149.- $US) and can use it when
your ignition cable from the coil to the distributor is exchangeable.

Joachim

----------
> Von: Danny Barrett <danny_tb at postoffice.utas.edu.au>
> An: DIY_EFI at efi332.eng.ohio-state.edu
> Betreff: Spark plugs/injectors
> Datum: Samstag, 9. Mai 1998 12:10
> 
> Does anyone know if it is possible to get spark plugs with fuel injectors
> built in? I have seen one of the list members write about keeping the
intake
> pressure as close to atmospherice as possible (and varying the
power/speed
> by the amount of fuel pumped in). There is one problem with this - It is
> very hard to get a reliable combustion from mixtures leaner than 18:1.
There
> is a solution to this problem (from what my Thermodynamics textbook
says).
> This is by charging the cylinder with a non-uniform mixture. ie: around
> 14.5:1 around the spark plug, and virtually nothiing elsewhere (where
> required). This, it has called "stratified charging." Apparently, engines
> have been successfully developed and run in the laboratory, but not in
> production cars (or at least, we've not seen them...). The book was first
> published in 1957, with the third edition (the edition that I have)
> published in 1980. I think it is fair to say that our EFI technology has
> advanced quite a long way since 1980. So... Why can't we build direct
> injection petrol engines that vary the mixture instead of the amount of
air
> going in? Since we now have sequential fuel injection, knock sensors
(even
> the Trionic one that we seem to hear so much about on this list - go for
it
> gentlemen...), etc... Why can't we make a direct injection petrol engine
> that uses a combined spark plug/fuel injector, so that we can use
stratified
> charging to our advantage? I reallise that there are problems associated
> with NOx gases produced in excess when lean mixtures are used, but isn't
> that what the catalytic converter is for? Also, wouldn't it be worth just
a
> little bit more NOx in the air (yes, I know NO2 is a poison), for the
sake
> of using far less fuel, and having less benzine rings (which can cause
> cancer) floating around in the air??? Or is there something I've missed?
> 
> Danny Barrett.
>