MTFCA Forum

Contrary to popular belief, this coil was produced between late 1916-1918 and replaced the brass top coil, mainly due to WWI where brass was a strategic material for the war effort. So, the Ford Motor company came up with a substance that was not considered "strategic" in any way. Wheat Gluten. But this substance had some dimensional stability problems all by itself, so they added one other component to make it both dimensionally stable but also rather heat resistant too. Asbestos Fibers.

Just how these cases were molded is anybodies guess, my guess is that they were injected molded (because the details are way too fine to be just a pour or even a heated pour for that matter) into a 3 part (probably water cooled) mold and that the spew way is in the upper left back corner, the "breathers" were 3 vent holes along the side opposite of the contacts, which when surfaced (cut) would also provide pressure points for the contacts against the coils box. But that's just my thinking on them, how they were actually done I don't really know, but one thing I do know is why you almost never find one of these coils "unmolested" (sanded)....over time the case tends to expand and so as not fit into the coil box, the reason for this expansion is the asbestos fibers absorb moisture, and the constant heating and cooling of the coil case, over time makes them expand out of shape to fit the coil box.

Ever build an evo distiller? I have on more than one occasion when stuck someplace where water was either rather scarce and or undrinkable....anyhoo what is it is basically a sheet of plastic held off the ground over whatever container you have handy, then place a fairly large sized rock in the center of the plastic sheet (sort of forming an inverted tent pointing down into the container), the result is that when the plastic sweats (distilled) moisture out of the air and runs down the inverted tent shape and drips into your well placed container. Gluten is a sort of an organic plastic, so it tends to sweat when it gets hot, which the asbestos fibers absorb (which doesn't help maintain its shape much) and of course expand, then when the coil cools because it's not running the car, the asbestos fibers retain the shape they had when they were hot and swollen a wee bit, over time this results in the coils not fitting into the coil box because of swelling. The common cure for this was to hit the sides with a belt sander, to get them back within the tolerance to fit within the coil box. As to whether or not the disadvantages of asbestos fibers occurs when belt sanding these coil cases, I'll leave you to guess on that score.

But this doesn't mean that these coils are dangerous, they're not, just that if you've ever sanded one....I hope you were wearing a mask (with a rebreather) and eye protection.

The other thing that seems to be in some contention in regards to these coils, is the front cover. There were actually two different types, the early type was a cast (poured) cover with a FORD logo on it much like the one molded into the rear of the case. The later style (probably because it was easier to mold, which of course in Henry's view equals "cheaper" umm oh yeah less expensive to make) was the rounded ribbed cover, which is the most common one you find.

Now as to their "innards" it's the same as the other coils and wires the same as the later coils that didn't have the bridges for both the points and the vibrator. These coils were discontinued after 1918 why? Probably because the customer complaints were more of a concern than the manufacturing of coils that nobody wanted to buy. Which I believe would be enough for Henry to make the decision to go back to a wood box case rather than this very unpopular Wheat Gluten case.


I have a couple of other coils to do and maybe the Master Vibrator assembly...haven't made up my mind on that contraption yet, but it was used on Model T (albeit briefly), so I guess I've got to do one at least, right? It's like I always say....fun never quits.

I should point out that the original points on these coils had a FORD logo on them, not the KW like I've got here, but since you can't find any points with the FORD logo on them, I settled for the KW points logo, which has the patent date of 1914.

Thank you Martynn V for the drawing and the short history on these unusual coils! I know that Ford made a bunch of them, but I haven't seen many in my years of swap meets and garage visits. I do have one and only one, which I somewhat restored some years ago. I have never had it set up on an HCCT or other tuning device, however I replaced the condenser with the modern appropriate one while rebuilding several coils for my own use. Mine was missing the one side piece. So I created a form from the other side, and cast a replacement side piece with the Ford script in it like a couple I had seen years earlier.
Interesting to see the two different sides in your drawing. I can't recall ever seeing one with the multiple ribs before. But then I have only seen maybe a dozen of the silly things up close and personal in all my years.
I keep mine as a curiosity, and potential show and tell item. Although not properly adjusted, I like the idea that it is a functional coil. I did a basic function test on one of those silly coil testers sold to the hobby many years ago. I haven't tried to run it in a car yet. But did check it for fit in a coil box with three wooden case coils. Seemed to fit okay.
About thirty years ago, there was a fellow (I forget his name) that had a beautifully restored 1917 runabout. It had a bunch of the one year only oddities for 1917, and he claimed it had four of the 1917 "plastic" coils in it. A few people that knew him well confirmed his claim.
I often wonder how many people around might have a full set of these coils in appropriate cars?

Thank you again for a wonderful contribution to the hobby!

I wonder if mice and other rodents chewed on the box and caused problems with them, Cars were kept in barns and sheds where these critters lived.

Martynn

Nice drawing of those fiber case coils.




As noted, the posts are molded into the top panel.

Ford's early adoption of plastic materials was ground-breaking, if not always successful. By the mid to late 1930s, plastic materials were becoming common in cars and other manufactured products, and most of these materials proved to be subject to decay over time. That problem with plastics has yet to be entirely solved. I'd guess that the gluten had as much to do with the coils decay as did the asbestos. As for cost control, Henry Ford's distaste for waste was designed and built into every Model T ever built. He made very little on each car produced, but he found innovative ways to make a great many of them, and he endeavored to eliminate waste streams or turn them to account whenever possible. A great many of the cost cutting measures were completely successful, and the proceeds accruing from the various cost cuts typically went into retail price reductions, not Ford's pocket. Many of the "cost cutting" measures, such as adopting steel over brass, or "leather cloth" over genuine leather, were driven by supply problems resulting from WWI, or from the very success of Ford and other auto manufacterers, as well as rapidly expanding demand from non-automotive consumers of materials like brass and leather, among many others. Both the American population and the American economy were growing rapidly during the Model T era, and demand for every sort of input was rising accordingly. Ford did a remarkable job of controlling rising input costs while at the same time reducing finished product prices. As for health hazards related to working with the Ford coils, anyone would be well-advised to avoid breathing any dust or vapor encountered when working on or with automotive materials, or any other friable or volatile material.

The wheat gluten cast Model T Ford coil was dimensionally unstable because wheat gluten is not resistant to humidity and water.
Ron Patterson