MTFCA Forum

Hello all,

Using my dad's Model T account as he passed away last year, leaving behind Model T's & A's ranging from a frame and parts in a field, to running '14 speedster, '24 Tourer, '26 Runabout, '29 Cabriolet (which everyone wants, but don't ask), '30 Coupe, another mostly there '30-31 coupe, pickup pieces and parts and parts of a TT in a field.

The '26 is at my place and am going through it to prep for sale and have had the joy (not being sarcastic) of learning about tuning Model T coils. I drove it around the neighborhood after washing and dusting, checking and lubing all the lube points, cleaning up and documenting/diagramming the wiring, and gassing it up. It ran fine until I picked up my wife A quick check and coil #4 was a No Go.

Fortunately, while watching some YouTube videos on all things Model T, I recognized a Strobo-scope as something in a garage cabinet. Brought that home and have gotten the coils in spec - still can't get #1 to NOT double spark, despite my best attempts using the knowledge from this forum.

I've combed through the maaany posts on hand crank, HCCT, FACT, Strobo-Scope and ECCT testers. The hobbyist passion and knowledge on this forum is amazing - everything from machinists to code benders to 'bailing twine will do' authors. Thank you all for sharing your knowledge.

Mark

Mark,
Sorry for your loss. Looks like he passed down more than just cars to you.
I thought my #1 coil was bad, swapped it with #2 and discovered that my '26 only needed a shim on the back side as it was not making contact while in the box. You did not mention whether the coil failed the test in the box or out of the box.
Vern

Vern,

Thank you for the response.

#1 coil is showing the double spark in the Strobo-scope tester. Using that, I was able to get the others dialed in.

I've tried all of the 'normal' adjustments and then some. Changing the tension on the cushion spring, tweaking the upper bridge a bit to change the open/closed gaps on the cushion spring, etc. With the contacts closed, the cushion spring isn't resting against the upper bridge. It appears that the tip of the cushion spring may have been bent down, not letting it fully return to rest against the upper bridge. I don't know if that could be the cause.

Mark

Cushion spring Gap is adjusted by the rivet that limits travel. Changing cushion spring tension does exactly that it adjusts the tension. What condition are your points?..worn & old ?....dirty, gummy ? .... What does the cushion spring gap measure out to?.......... Attached photo from previous Forum posting gives a good approximation of starting measurements before adjustment procedure results.

Gary .. Possible to post close up picture of your installed coil points ?

Moxie - thank you for jumping in.

The image you shared is what I've been using to adjust the cushion spring tension and gaps.

Loosen the two nuts that hold the lower vibrator and have the points position squarely, then tighten . To correct your double sparking, the cushion spring tension may have to be increased , along with your vibrator spring tension according to the test system that you use......... Looking at your pictures, looks like some dirt and oil.... Using some brake cleaner spray to clean out under the cushion spring and top of the coil will help to give more accurate electrical coil settings.

Moxie - thank you for the feedback. I'll give the coil a good cleaning.

I've gone down the road of increasing tension on both springs and then dialing the coil in on the Strobo-scope...but I'm a newbie and will give it another try or two, or three and report back.

Here's a post-drive photo from today.

After several hours of fine tuning, torturing, tweaking, folding, spindling, and mutilating... the coils are now mostly behaving.

I ended up with the gap on this coil at around .021. I suspect if it was put into an ECCT, that it would show the firing timing to be off from the others by a few degrees, but this is probably good enough for my purposes.

If it gets up to about 40* today, I'll take it out for a drive.

mw

Just a few questions... Did you test the capacitor or change to a new capacitor?... Did you wire brush the three-button contacts on the coils and re-tension the terminals inside the coil box holder.... And what were your strobo spark results?..... Just curious.

The answers to your questions.

I tested the caps on the Strobo-Scope. All coils/caps tested fine and with no leakage.

I didn't brush the contacts, but I sanded them with contacts closed, grit up and then grit down, so they'd make a flat contact and then polished with 1000 grit, then re-aligned them on all coils as per your recommendation.

I didn't know tensioning the terminals inside the box was a thing...guess I'm off to do that now!

Took it for a soda and fuel today.

Hey. TYM452...... CAR STILL RUNNING TO YOUR SATISFACTION?