Paul... I do not recall Msd calling their 6AL2 a capacitive discharge system.
 I believe it is a simple multispark system. I called the factory and asked
what was the difference between the 6AL and the 7AL2 and was told after MUCH
HEMMING AND HAWWING that the 7AL2 was a true capacitive discharge sysetem
that also multisparked. If that is true that is a world of difference.

JIM DANA

Wow. You are right Jim. I just read the ads in Summit catalog and nowhere
do they mention CD. Summit does not list the 7ALxx in the July Aug 2000
catalog.

There I go again assuming. Just because it was multiple spark I assumed
it was CD with a short spark  and  needed to fire repeatedly.

In order to fire rapidly repeatedly you need to get the pulse voltage up
due to the high inductance of the coil primary. Perhaps they just use a 300 volt
DC supply. One could say a 300 volt DC supply has capacitors to store
the charge :-)
Paul Lamar

The MSD web page is at http://www.msdignition.com/ The multipal spark part of all of the systems only operate at low RPMs. Up to about 3000 RPMs. Great for keeping the plugs clean. As thr revs go up to where a Race engine is used, there is no time available for this function. There no multipal sparks. The electronics, (probably a mulitivibrator) pump up a large capaciter through a transformer to 460 volts (in the 6AL) and when triggered, disconnect the transformer and strap the capaciter to the primary side of the coil. This is quite a surprise to the 12 volt coil and the rise time is very short. The capaciter and transformer are in all of the ignition boxes that Autotronics makes. They also
make programable fuel injection systems. You can download installation instructions for any of their systems from the web site. Very interesting. Why they don't say that each and every one of their systems is a capaciter system, I don't know. Every one I have looked in so far has been a capaciter system. I notice that the 6AL system will run down to 5 volts. That could be a life saver some day.
Lynn E Hanover

The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org