What is the best high tension mag for the Model T
I am looking for the best but simple design to start production, any input welcome. Bob
The best and most reliable ignition system is the original system. It works with battery power or self generated mag power and has the real benefit that knowledge and parts are available to fix it most anyplace in the world. You can't say that about any other after market ignition system
There used to be a mag made for light aircraft right there in Rockford. Can't remember the name, but somebody will. It was cheaper than the conventional Bendix mag.
There may be some good knowledge among the retireds around RFD.
Of the era type magnetos, I really like the Splitdorf. I have used several of them and they just plain WORK. The truly great feature is they have a mica insulated "condenser" (capacitor) that never seems to fail.
If you want something new you can just buy, this is probably the best but sure not cheap at $1395.00
Ricks, I think that might have been "Slick" mags. I'm on my way to Bakersfield, I think I have one stashed away, will look when I get back.
Ralph - This may not be what you are thinking of, but there was a company called Woodward Governor in Rockford back when I was working for International Harvester in Hinsdale, Illinois in the '60's. They had an excellent reputation and I'm thinking that they made magnetos as well as governors.
Bob, all the early ones, if maintained do a good job. IMO , the most plentiful , easiest to maintain and get easily repaired is the Bosch DU4. They are so plentiful i cannot imagine it being worthwhile to reproduce one. Do you possibly mean the magneto drive attachment?
I guess it depends on what Bob means. If you are talking about reproducing just the high tension mag, there's tons of rebuildable DU-4s out there and several folks rebuilding them. If you mean an accessory high tension drive unit, then there's a few different ones to consider. I have a Bosch Triple Gear drive that is great for early non-generator cars. I'm even having new modern profile gears made for it. Another option is the Bosch chain drive, which would work on gen and non-gen cars. Then the cross drive, where you replace the front plate with a plate similar to a distributor, but it has a mount for the mag to sit angled down and sideways in front of the engine, that'd work on both kinds of blocks too.
I like the Bosch DU4.
Running one on a test rig.
As mounted on a non-generator engine with an accessory drive pad.
Yes, Don, it was Slick; thanks.
Look for me being pushed around in a wheelchair.
I'm with Frank about the Bosch DU4 or DU4/2.
If it's a mounting bracket you're thinking of please make it long enough to accommodate a mag with an impulse coupling.
With an impulse there is no need to "spin" the engine over to start it.......
I like the Simms SU4, which is basically a clone of the Bosch DU4, except that it has an exciter circuit so it will start easily without an impulse.
How does the exciter circuit on a Simms SU4 work? Does it need an external battery so it works as a distributor system when starting?
After having worked on many different brands and models my favorite is the Bosch ZR4 as seen above on a Mercer Raceabout. They are one of the most
advanced types of early magnetos to be found. Benefits are: they are very reliable, put out a real hot spark, are available as a dual unit for starting on
battery but will also work fine without it, two-spark versions will fire any two plug heads or racing overheads, and prepped correctly they are quite waterproof.
I do not take in any mags for rebuilding, but you can follow along and learn as we rebuild this Bosch ZR4 2-Spark Magneto in a four part series on
TheOldMotor.com @ http://theoldmotor.com/?p=26928
Roger, here is a description from:
THE AUTOMOBILE Page 688 April 13 1916
Ignition on the Maxwell car is furnished by a Simms high tension magneto assisted by dry cells and a transformer coil to facilitate starting. The ignition system is of the dual type, having a small non-vibrating coil which is attached to the frame of the car. This coil is unaffected by either moisture or heat, and being non-vibrating there is nothing to get out of order or require any adjustment.
Four dry cells are used in connection with this system, and care must be taken to connect them correctly. This is most important, and the wiring diagram should be consulted before disconnecting or connecting any of the ignition wires.
The switch operating the battery circuit is in connection with the starting switch and when the starting pedal is depressed, thereby throwing the starting motor into operation, the current flows through the switch, coil, and magneto. As soon as the engine starts or the starting pedal is released, the circuit is automatically disconnected and the engine runs on the magneto. It is readily apparent that the operation is extremely simple with the additional advantage that it is impossible to unconsciously leave the swtch on and thus run down the batteries.
To start, the spark should be fully retarded__not only to eliminate the possibility of back-firing but because the spark is actually hotter when the spark control lever is fully retarded, with the engine running at a very slow speed. At medium or high speed the best results are secured with the ignition partly or fully advanced.
Ok, it needs an extra coil in addition to an external battery. I was curious how they avoided demagnetising the magneto if they were introducing battery power into the magneto, but I suppose it's just going through the points and the condenser, never into the magneto itself. Not sure how the spark from the extra coil gets distributed to the plugs, though?