MTFCA Forum

So I’m building a 13 engine and I have several mag coils.
A “tin” disc
A double stack
A single stack

Which is correct?

They are all freshly rebuilt

The 13 has a field coil all by it self, it takes the small round double stack,the magnet plates are the long ones, Years ago Wally told me these where the ones that gave every one the broken wrist. I would run the double stack oval that is 14 year and have no problems, noe one but you would know what is in there.

All ‘13’s had double stack field coils. Most I’ve seen are what Joe mentioned.

What’s in there now might not be original.

How thick are your magnets? I think the change from 5/8” to 3/4” magnets was late ‘12 or early ‘13..

If you have 3/4” magnets, then the earlier tin field coil wont work. If you have 5/8” magnets, the single stack won't work (won't function very good and would need 1/8” more shims).

The engine is being built from parts so I will see what fits.
Thank you

Single stack is 1917-1927. Starter notch added 1919. Ribbon reduced from ¼" to 3/16" 1923-1927.

You can install a later, starter type field coil in a '13 with its original narrow nose pan if you use the later flywheel and magnets as well. It can even have the starter ring gear if you want to put it in. That's what I did on my '14 one day when Original Smith wasn't looking but he has since marveled at the way it starts and runs on the mag. I have no battery in it.

Hi There, here the Magneto restoration R.V. Anderson did for me. My 1914 speedster is really please with it. Well done

Mario
That coil certainly looks similar to the one I have.
If I add a electric starter, it will be one that fits on the front of the engine!! I have two of them, one is original and one I “invented” using a one wire alternator and a Subaru starter (it turns the correct way). Either way I will install the cog belt pulley when I assemble it!!

Somebody had installed a single stack coil in my 14 motor so I replaced it with a rebuilt single stack coil. One of the brass screws broke so I had to remove the flywheel, I replaced the long magnet clamps with the later style because I think the longer clamps were made for the round coils. It starts fine on mag, really well since I individually charged the magnets.

If I was rebuilding an older engine it would have the 1/4 field coil with a ring geared flywheel in it, no one will know and some day we are all going to get old and hand cranking an old car or hitting a starter switch is the choice you may take some day of driving which car, I have seen it happen many times and the non starter car will set!