Aden wrote:

I just uploaded details of the supplier, and then saw this and another
message from Mr Tracy Crook (may I call you Tracy?). A couple of points:-
The transformer used is rather critical in terms of air gap (reluctance) for
efficiency, and the 1uF capacitors must be of the type specified for
longevity. The ICs and IRF822 FETs are from International rectifier and are
a bit
difficult to source here in Oz. A data sheet for the IC is available off the
net.
The FETs are not critical, but must be of the same type with integral clamp
diodes
- Siemens (Philips) BUZ42 work fine, MTP3055s are available everywhere
(Motorola).

I also note Tracy's concerns about the validity of using a substitute for
the Mazda ignition
system. I know nothing about the stock Mazda ignition, but from what has
been written,
I infer that it is non CDI. If this is the case, then there are distinct
advantages to be had in
using CDI - particularly for lean burn conditions. I agree with Tracy
regarding the selection
of quality coils, and point out that even though I did not find any problems
with a new
standard coil (the oil filled, metal cased variety) commonly available
(although many times
during testing, the coil's internal spark-gap arced over), I have only built
two of these units
with these coils.

However, my concerns lie elsewhere. i.e.: Firstly, this is a kit; and not a
thoroughly tested
production item.  As such it requires thorough testing in its intended
environment under load
conditions as it will be a critical item in the airplane. Secondly, this is
not a kit suitable for
someone who has not soldered before unless constructed under experienced
guidance.
Whilst the article gives good clear directions on assembly, one bad solder
joint (dry or
peaked say) around 300VDC will likely cause failure in time. Now having said
that, I do
think that with meticulous attention to detail, and given the level of
redundancy planned (one
unit and coil per plug) I  believe it to be a practical construction
proposition.

Its your call.

Kind regards to all.
Aden

 
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