Saturday, November 12, 2016

Electronic ignition is done - I think

Trickier than I thought. (As usual click on the photos to see the full version.)

I started out by modifying my electrical drawings, which was kind of fun.  I had to add in the four coils, decide where the connections were and assign wire numbers.


Then I had to modify the switch connections on the instrument panel to get rid of the magneto P-Lead ground path and add the +12 volt power supply to the coils.  Glad I managed to remember


how to use the Solid Edge CAD program.

Well, it turns out the hard part was finding a spot for four additional coils. I was hoping to attach them to my plenum in some fashion, but my friend John Cotter talked me out of it - and he was right.

Finally, I decided the only space available was the compartment that the magnetos previously occupied, the cutout in the firewall.  John came over and helped me install these rascals. I think this installation will work, and I can actually reach in and get my hands on the coils, with the engine installed, for what ever reason may come up in the future.


It was a bit of a bother finding which spark plug wires to use, but I settled on the MSD Street Fire line.  In retrospect I wish I used Magnecor, since they seem to be higher quality, but since I have $60+ invested, I'll keep them until I decide they're a problem.


Now that it's all done,  I have been able to start the engine several times and it runs a lot smoother, especially noticeable in the lower RPM ranges. I think I'm going to like this setup. It's kind of odd pulling the prop through and not hearing the magneto impulse couplings clacking away.


So for now, I am waiting to test fly until I get a letter back from the FAA giving me my flight test area limitation.  After five hours in the local area, I'll be good to go.




1 comment:

Jim Scoles said...

Hi Sam discovered your blog last week and have read it all now, well done. I have a C 85 powered Tailwind with an electronic ignition that I made up from the Megajolt system. I have another take on the trigger wheel you might be interested in. My email is jimscoles66atgmaildotcom send me a note and I will send you some pictures. Also would love to talk timing curves.
Thanks Jim