Buick Model F Splitdorf Coil Box Modification

[Mark Shaw]

Buick Model F Splitdorf Coil Box Modification

     My Model F came with two cut down plastic Model T coils with wires & bolts soldered to the side & bottom connections.  I had nothing but trouble with them on my first 1 &2 cylinder tour last summer, & I wanted to be able to just swap coils if I have ignition problems.  The original Model F Splitdorf coil box takes specially made coils available in Snyder’s Catalog at $465 each and in Lang’s catalog for $546 each.  Call me cheap, but I cannot see paying so much for trembler coils when used Model T coils are under $20 each.  So my challenge was to modify the coil box so Model T coils can be swapped out when one goes bad.

     I had to sand the narrow end of each T coil (only about 1/16” from each one) to make them fit back to back in the box.  The wood was a bit warped and sanding them with my belt sander evened them out and removed just enough to make them fit snug.  I soldered the bottom battery connection bolts to flat “contact washers” that fit perfectly inside the recesses already in the box.  Using a ½” wood chisel, I made grooves on each side the box for the timer and spark plug contacts. I evenly cut four contact strips from the Bottom of an old Model T ignition box to install in the side grooves so only the spring contacts sit proud of the box ID.  I soldered wires to the backside of contact strips and used a wood burning tool to make channels for the wires from the contacts to the open space inside the front of the box which provided a wire run to the bottom of the box behind the ignition switch.  I then cut the wires to length and soldered contact bolts to the ends of side contact wires and installed them in the bottom of the box.   I used shortened nails to secure the contacts inside the grooves and epoxied the wires into the wire channels. 

     The completed coil box modification worked perfectly with all three Model T coils I have.  It may not be pretty inside the box, but none of it shows and the T coils provide excellent spark and will allow me to swap coils if needed.

Mark Shaw

Vancouver, WA USA

Edited November 29, 2016 by Mark Shaw (see edit history)

[dibarlaw]

Mark:

Great modification. Good thing that us car guys who do their own work have a healthy respect for money. Otherwise no one would attempt to do these modifications. I spent 2 hours last night re-working a new combination switch housing from BOB'S. If I was not having an issue with him exchanging a new wing nut for my 1925 Master. I would have sent the switch housing back I purchased from him as the quality was pretty bad. I had gotten a new housing from him 4 years ago for the 1925 Standard which I rebuilt. It was a much better casting although some modifications still need to be made. I believe his supplier made an RTV rubber mold of a good original. Making the new aluminum castings from this mold makes all dimensions smaller because of the metals shrinkage.The casting I just received has many gas holes and inclusions. It is just barely useable. Also one has to adapt the original micarta contact plate to fit.

 I just feel for those in the hobby who do not have the experience /skill or machinery to make those adaptations.

[Mark Shaw]

Larry,

     I fully agree.  Those who are in the catalog parts business should share the responsibility for quality of the products they offer in their catalog.  A single hobbyist does not have as much sway as the catalog house that sells a significant quantity of the manufacturer's product.  Casting voids and dimensional differences in replicated parts should justify replacement by the supplier regardless of when the part was purchased.