This might be a question for Lynn, Ed and Tracy. I am trying to get
 > together the motor controls for my 20 B. This question
 > would be good for all rotaries though. Do you fire the ignition
 > using the "rotary split" or fire all the plugs at once? I have
 > been advised by some people who should know that the split
 > between plugs isn't needed. Just fire both at the same time. Lynn do
 > you time the firings on the car? Ed and Tracy, same time or sequential?

The 13B will keep making more power up to 37 degrees and more, but the waste
heat goes way up after 27 degrees. The race 12A Max is 27 degrees just because
it is a bit smaller.  That is for best power around 9,000 RPM.
There is a lot more time for the burn at 6,500, so best power timing may be
22 to 24 degrees.

The airplane is a great dyno, so best timing should be easy to come up with.

The split timing is required for pollution, and a few foot pounds at lower
speeds. It adds complexity and is of no value in aircraft.

You can fire both plugs at once. That way you can run two plugs with a coil
on plug each, or a double ended coil and two MSDs, and no distributor.

We fire both at once at 27 degrees but there seems to be no difference
between 25 and 27 on the dyno.

Lynn E. Hanover

 
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