1910 magneto timing Model D

The Bosch DU1 mag on the Model D was found to have a bad coil, currently having a new coil rewound from the core, and will be ready to start. My question is do any of you have a mag set up with a traditional timer coil battery ignition? My coil box has a two key position switch and it is an original box and switch, so I am thinking it can be done, just not sure how. I got the car in a basket, so no history there. The mag was a rare option as it was $40.00. There is only one spark plug not two. Thanks for any input...John Ullrich

John- I have been wondering the same thing. Since I am still in the process of finalizing getting my engine ( running off the battery) and transmission running properly the magneto has not been a priority but it sure would be nice to have the mag hooked up correctly . Hopefully someone will have info/photos to share .My roadster ( which originally came stock with the magneto) has the original DU1 which I had rebuilt a few years ago and I bought a second one and had that rebuilt for a back up but one thing that I am missing to make it work ( besides the wiring) is the coupler that goes on the shaft of the mag and then mates up with the corresponding part on the engine . By chance would you have a picture of that coupling that you could send to me? I saw a few Brush cars years ago with non original magnetos and non original timers . I think somewhere I have some pictures of how they were wired . I will try and find those pictures and post them . My car has two spark plugs ( both valve caps have plugs) and the cars I saw years ago and those that I have seen on the internet also have a plug in each valve cap. Side note- the advice you gave me awhile back about my transmission issues has helped considerably and I hope that this coming weekend will be the first time in almost 60 years that my Brush will move under its own power. Scott

Scott, that has to be the answer...two spark plugs, the one over the intake would be for the start from the battery-coil ignition and then a switch to the mag side and the plug over the exhaust valve is for mag. My car has only one plug the exhaust does not have a hole for the plug. Does your DU1 also have a set of points in the front with an advance and retard ? Then separate a timer for the ignition with or without advance and retard? I would think that advance and retard would then only be on the mag side after you start you switch to mag side and then advance spark or retard accordingly. The coupler is an easy deal. I will send some photos as soon as I get it out of the shop. The shaft on the mag is coned and one portion of the coupler bolts onto the mag cone end. the coupler is a three piece set up...one fits the shaft...one in the center and one which is pinned with a drift pin on the output from the cam gear... they are round with interlocking "ears". John

Hello guys,

Perhaps you could take a clue form Model T Fords, the coil box switch selects the source of energy for the coil box. Battery or magneto, remember in those days the terminology for a magneto also included what we call today a generator. Start on battery for good spark at hand cranking speed or with any luck " start on the spark", then switch to mag to run by generated power and save the battery which was usually dry cells. The timer and vibrating coil and one spark plug per cylinder were always in use both battery and mag positions.

A high tension magneto such as the Bosch DU-1 fires the spark plug directly and uses shaft energy to make the spark. This requires faster hand cranking. The switch to control the Bosch magneto would be a simple grounding switch to kill the mag.

These would be 2 mutually exclusive systems as I believe the coilbox switch is not capable of controlling a high tension ( Bosch) magneto.

What does your parts book say about ignition parts?

John- first picture is the original mag to the car , second picture is the mag gear inside the engine, third picture is my spare mag , fourth shows cam gear with ears and obviously where I am missing the coupler. Does all of your set up look like this? Do you know what the connection on the front of my mag is ( first picture)? I have a reprint of an original manual for a DU1 and even after reading thru that I still don't quite understand how things are to be properly connected. Sure would be great if someone out there who has a Brush with a DU1 could post some pictures( or maybe any mag set up). Layden B- I am not aware of another switch besides switching from battery to mag on the coil box although the parts book does mention (see attached picture) a " Dash Switch" but only for the standard Brush model 24 and not for the model 26 roadster. Originally the Bosch DU1 high tension magneto is what some Brush cars came with if - although there may have been other mag options that I am not aware of. The instruction book talks about a switch on the floor board , although mentions nothing about the coil box. Roadsters and delivery vehicles were apparently the only models that came standard with a magneto and the other models had to be converted or specifically ordered to have a mag. Every Brush I have seen in person looked to be non magneto cars originally as their coil boxes ( no "mag" position) are different then mine which has the "bat" "off" " mag" ( see the picture in my first response to John's start to this thread) positions on the coil box. Although most of the cars I have seen had non original Brush coil boxes. I don't remember and cant locate my pictures of cars I have seen in the past that had mags added to them so I just don't have much to go by physical comparison. Scott

Thanks Layden B , I totally get Henrys approach to the coil, battery, timer system. On the T you switch over to mag and run off the same timer. I also am unaware of being able to operate the Bosch Mag thru a battery-coil ignition and then switch over to mag as on a T thru the same timer. That was the question to the forum....does any one have a mag system and a battery coil system on their car and if so are there two separate timers which is the only way that I believe it could work. It would require two plugs and two separate timers one each for each system...coil or mag. Scott it sounds as if your car was equipped that way. Hence the two plug set up and the switch with a battery and mag designation..My switch has a two position battery key and is a brush switch. But my car only has the mag and no timer. So....the question remains does any one know if it is possible to use the point system in the Bosch mag to run in addition a coil battery system for start? Scott the connection in the front of your Mag is for the ground wire that goes to the switch on the floor board which will turn off the engine. You wire from there to the switch and then to a ground on the engine [i use the cover bolt for the rod inspection plate]. Your also right about the connector for your mag, it interlocks in the piece you have and connects to the piece on the shaft. Interestingly, the woodruff key in the shaft is not used for the connector. It was designed to be used for a chain drive application as the same Mag is used on early motor cycle engines. Mag still in shop will post picture of the connector when I get it. Thanks guys, John

I have attached the photos of the connector link for the DU1 magneto. The inserts are at a 90 degree position which allows the "ears" from the shaft connector and the engine connector to interlock.

John- The serial number on the mag that is on my car looks like it would be around 1911 and it is marked Mod 5. My extra mag is much later as the serial number is 2,717,932. Scott

John- this shows the two spark plugs and the Kingston 4 ball. As I mentioned earlier today I am soon going to take the 4 ball off and put on a Holley NH to hopefully make the engine run a little better. Going to do some more work on the Brush tomorrow and maybe tomorrow will be the day for it move under its own power for the first time in over 95 years. If it happens tomorrow I will update you.