The foam is a very poor substitute for tar. The tar is to hold the solder joints and everything else from vibration. I have repaired many with either nothing or foam added when rebuilt and come to me with solder joints just broken with vibration and never one returned that was completely full of tar...with nothing left to vibrate.
ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ICgqoV7e2kc.html Rather than tearing the coil apart this man mounted the cap externally, which would help heat dissipation. He also thought the gap between the iron core and the bottom blade should be .032". I would imagine Ford would have given a spec. on that back in the day because Model T owners wouldn't have the test stand you show in Part 3 to set amperage. For anyone not concerned about original appearance i would think externally mounting the cap is a good idea.
"When I was a kid" (I'm 73) I used to go out on the short piece of sidewalk in front of our country house, hook up my train transformer to a T coil I found in the garage, and with a ground driven into the earth and a wire on the "spark" output, I used to "lightning strike" ants, beetles, and other unhappy mechanisms
Simple buzz box coil testers are useful for testing coil primary and secondary windings good and not arcing internally. OK for 1 cylinder engine but 4 cylinder Model T engines require all 4 coils to be adjusted for equal and consistent firing Time. Coil current was used as an indirect approximation for ignition coil firing time because there was no accurate way to measure fast (0.002 sec) spark events back in the day. Today, digital electronics makes that task easy and very accurate using the Electronically Cranked Coil Tester (ECCT), learn more about that here: www.modeltecct.com
Please reconsider your use of expanding foam to replace the tar. 1. The expanding foam is an insulation . So the box may feel 'cooler' because the foam isn't conducting heat to the exterior as well. 2. I would be shocked if the dielectric strength of the polyurethane foam is anywhere near that of the tar. 3. Having worked in a factory that builds radio units for utility companies, the potting compound used now is still has properties remarkably similar to tar. Even though it is epoxy based and far better spec's overall the tar is still a better choice for the coil box than polyurethane foam I suspect. Good video. 👍
The smaller, 630V capacitors at 8:11 appear to be the incorrect type (Metalized Polyester Film type; eg. Panasonic Type ECQE(F)) with low dV/dt rating; if so, they will likely fail with use in the Model T ignition coil application. The larger, lower voltage; 400V capacitor at 8:25 appears to be the correct type with dV/dt rating >600V/us which is required for the ignition coil application. The next important step is point adjustment for equal and consistent firing time. For that, there is no better tool than the ECCT. It is the only coil tester that actually measures dwell time to fire spark. More information here: www.modeltecct.com
It might be better to mount your camera above your work area because your hands were blocking the view of what you are doing. Had to guess at what you are touching with the test leads.
Donald Haas I am new to model t. What does it mean when they o Meter flashes to about 13 - 1500 on the side post and then goes back to nothing. From the top post to the bottom post you get 002 on the ohm meter. I bought the tester from Snyder's and when you put it in the tester with a 6 volt battery attached to the tester and open the points at pegs the needle out. Did you get offer any help it would be greatly appreciated
