A few weeks (or months) ago I posted in this forum a few questions about the rebuild of some (3 different) early Heinze Coils.
Here is an update of the state the coils are in now and what I did.
First I had to find out what coils I had.
One was easy, it said 1914 Ford on the coil and it was so. I found this coil can be used in a later coil box and have the same dimensions as the later coils.
The coil with the sticker "Heinze 1909-1911" is actually a 1913 Heinze coil.
The coil with 1909 on it, is an early 1907 - 1908 coil and was used in the Model S and early Model T.
The 1914 and the 1913 coil needed a total rebuild.
For the 1914 coil were no points available. I cleaned them up and made the best out of it. There are other coils and a new capacitor in it. The 1913 coil had new points, capacitor, insulator, top plate and other winding primary and secondary. This coil needed also a box repair and reinforcement.
Both coils are sparking at 1.3A on my HCCT.
The 1907 coil have only new points on it. Here I have a problem to make it buzz right on my HCCT.
With the adjustment screw I can make it buzz at only 1.2Vac than it need 0.5A and had always a double or triple spark. As I turn faster the HCCT to 2Vac and turn the adjust screw I get a single spark at about 0.9A. At 1.1A the coil stop working, I never have 1.3A as the others.
I am wondering if I should build also other winding and capacitor in it to make it buzz right.
In attachment a few photos
When you say at 1.1A the coil stops working, do you mean it stops buzzing and just goes dead, or that it buzzes but does not spark? If it's still buzzes but does not spark, I think the coil is shorting internally when the discharge energy gets high enough to overcome the old internal insulation. I use this style of coil in my Model N. I believe I was able to get them up to 1.3A, or somewhere near that. Getting double sparks with those coils is hard to avoid as there is no cushion spring to prevent the point contacts from bouncing off each other.
All that being said. Those coils work really well in my N.
Contact RV Anderson. The correct amp draw on the early coils is significantly less than the later coils.
The "1913" coil is actually an early-mid 1912 style. In later 1912 Heinze changed to using a single piece armature.
The "1907" coil is actually a 1908 style, and was used only on the Model S. It was not used on the early T except perhaps on one or two prototypes for testing purposes. The S Heinze coil unit is used in a coilbox that has porcelain sleeves as high-tension insulators on the bottom. The 1907 style uses hard rubber sleeves that thread onto male fittings attached to each individual coil. The coil tops are quite different from the 1908 style.
Your amp draw of 0.9 is fine, and if the condenser is good and the coil is physically set up properly it should give a good spark. Richard is correct that the early coils' amp draw is less than later; this is because most early autos including Fords used batteries for ignition, and a higher amp draw runs them down more quickly. The instruction label in the lid of the Jacobson-Brandow coilbox used in 1910 states that the amp draw should be 0.2 amps. That's right; two-tenths of an amp.
Thanks for all the information.