I would like to eventually install this mag on my car so that I can use the Rajo BB to the fullest extent.
How should I make the wiring harness?
What gauge wire should I use?
Can I use the stock generator?
That looks like a Matco cross drive mag adaption. I can't imagine what kind of wiring you need...other than a ground wire to kill the mag. Of course spark plug wires. If you have a BB then you don't have a dual ignition system...but that doesn't make much difference.
The generator has nothing to do with any of this.
Oops...I didn't notice the dual spark feature...that should be fun working that out. I'm not sure what that is about. By the way..that Matco is set up for a generator engine.
I understand a ZR4 2 Spark dual fires 8 plugs.
it only has 4 towers on the cap correct? dual spark is so you can start on battery, and switch to mag like a normal T. is there 2 terminals on the point cover? if so, one is ground to kill it, and one i believe is for a battery connection.
Yes that Bosch ZR 4 twin spark magneto is appropriate for a Rajo BB twin spark head. Yes with that cross drive front plate you can use a generator. Wires are easy, just use the normal Model T spark plug wires with the brass plate for the front studs and on the top connections strip off the brass plate, strip off the insulation but leave 1/2" of internal wire and bend it back over the insulation and push it in or use modern dist. cap metal connections.
What I am curious about is how it is connected internally.
Tim, you seem to be knowledgable about this mag;
1. How many sets of points does it have? One or two?
Les: this is a good article see about the ZR4 two spark.
So their description is consistent with my thoughts. The dual plug version fires a plug from each end of the "high tension " winding, rather than having two high tension windings as some have thought
Unless it is hiding behind the large drive gear in the photo...you are missing the drive tang that screws onto the cam at the cam gear.
If that is a twin spark, dual ignition DU, it is a rare beast indeed. Below shows the aforementioned drive nut, and a wiring diagram for the dual ignition.
Sure doesn't look like the magneto fires 8 plugs.
all the wiring diagrams i've seen are using the real bosch switch and coil which is expensive stuff. why wouldnt the stock T switch and a 6volt coil do the same thing? i have the du4 with 2 terminals on the point cover
John - notice that 4 plug wires come out the front (black knobs) and 4 more out of the top.
I run a BB and 20 years ago when I was building the engine, ZR4 2 spark duals were not common and the one I did find was $2400 reconditioned, a bit over my budget at the time so I went with a Mitsubishi distributor that fires all 8 plugs.