Old Lesson re learned on low tension ignition for a Red Devil 1903

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Engine builder, Blown V8 to wobbler, Love it all.
HMEM Supporting Member
Jan 24, 2012
Reaction score
Crockett calif
Well I just completed a Red Devil from Shelf Pet Models. It has low tension ignition .
After trying different point metals , I settled on tungsten. Iron makes a big spark but erodes fast and guess where that
iron spark slag goes. ?? I also tried various coils from a extremely low resistance model MJN .01 ohm?
made for models , and some auto coil primaries.
But the old lesson re learned was fluorescent magnetic ballast inductors . Old school ones. I already learned this one as I have
an Aermotor 8 cycle model running on an old ballast lamp inductor. But I had to re learn . The improvement is remarkable
the ballast I ended up using was mentioned elsewhere on HMEM. It is a GEM120ph120/2-diy. Ebay guy sold them to me for an offer of 10$ ea for 4. So after getting it to run hit and miss at 12v on 1 coil I tried 2 coils in parallel. Yep much better.
More range of fuel/air acceptable. So I went with 3 in parallel, no real improvement but too much spark?? I don't think so.
Each coil is 590Mh in inductance and about 37 ohms in resistance So at at ~10 ohms in parallel 1.2 amps with the points closed
It is trivial current compared to the other coils I tried. Just thought I would share. I will post a Red Devil post on completed
projects soon. With a crappy youtube video link. Thanks to the forum for reminding me of this. I am off to the Frisco Standard
with dual low tension ignitions! Yea I am a glutton for you know what.


  • 20210716_190635.jpg
    181.9 KB · Views: 79

Latest posts