Tracy Crook wrote:

I'm confused.  In my experience, even .016 is an anemic gap.  Check

out the

gap on a stock Mazda rotary plug (not adjustable).  It's something

like

.040" - .050".

BTW, The coil energy on the stock Mazda coils is very good, and being

an

inductive system, the spark duration is very long which is what you

want

under lean conditions.  CD systems have a very short duration.  MSD
(multiple spark discharge) has to make many sparks to make up for this
shortcoming.  It also eats a ton of electrical power which may be of
interest to those concerned about battery life in the event of

alternator

failure.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

I thought the rise time of the CD was important for punching
through plug contamination. At least that is what they told us.

snips..

Don't read this if you just want to fly :-)

Here is a chart from Heinz Heisler Advanced Engine Tech on the
abilty of the CD to fire a partially fouled plug.

BTW I would love to buy motor mounts and all the other parts
Norm mentioned off the shelf for a rotary and my Kis Cruiser. You can
always buy a Power Sport firewall forward package if you don't
care to do it your self.

Paul Lamar

Tracy Crook wrote:

Yes, fast rise-time and the ability to resist plug fouling is the main
selling point for CD ignition.  But plug fouling has not been a problem for
me during 6 yeasr and 1000 hours of rotary flying.  I will admit to some
bias against CD ignitions.  My medical X-rays look distinctly mechanical
(and I walk kind of funny) due to a horrendous airplane crash.  The plane
involved was powered by Evenrude, not Mazda rotary .  The power failure
which caused the crash was due to a failed SCR (silicon controlled
rectifier) in the CD ignition system.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

OK Tracy I can sympathize with that.

Paul Lamar
 
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