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Splitdorf Magnetos

    Splitdorf manufactured many, many magnetos over the years.  It is beyond the scope of the page to cover all of these.  What follows is a brief discussion of some of the Splitdorf magnetos used on American motorcycles.

E series
The "E" series high tension magnetos were built for a variety of motorcycle configurations; single cylinder (EU), V-twins in 42, 45 and 50 degrees (EV), 180 degree twin (E2), and four cylinder (EU4).  The construction of these magnetos include an aluminum base to which the pole pieces are secured, and between which revolves and armature on two annular ball bearings.  A pair of tungsten steel magnets straddle the pole pieces.  These are covered by a ribbed aluminum cover that is designed to keep out dust and dirt.  These were used on Indians as well as other makes of the early teens.

    The Mag-Dynamo was a combination high tension magneto and dynamo (generator) available from about 1915-1918.  The dynamo armature which generates the direct current is placed above the commutator.  The magneto armature is located below.  The magnets are not of the permanent type, but are of the "electro" type, excited at first by the battery or the first few revolutions of the generator.  The dynamo and magneto are seperate and distinct otherwise , but combined in one unit.  It was offered as an option to replace the standard magneto when eletric lighting was specified.  These were used by Indian, Excelsior, Dayton, Thor, Pope, Harley-Davidson and Merkel.   Rated output of the generator was 3.0 amps, 7.5 volts at 1400 engine rpm (about 30 mph).

Splitdorf Mag-Dynamo parts list

Dixie Magneto
    The Dixie was an revolutionary magneto used by automobiles, airplanes, boats, stationary engines and motorcycles. Perhaps a testament to the Dixie's versatility and dependability was that it was manufactured  in a wide variety of models from 1 to 12 cylinders.  Two important aspects of the Dixie are 1) it uses a rotating magnet principle in which the magnetic lines of force do not have to change direction with each revolution.  This allows for a hotter spark at low speed.  2) With most magnetos the intensity of the spark is dependent on the position of the advance lever.  A specific position will provide the most efficient spark, any other position will cause a decrease in the intensity of the spark.  This is not so with the Dixie.  It's design allows for the spark advance position to have no ill effect on the quality of the spark.  One problem I have found with the Dixie is the base.  It is made of a zinc based alloy (similar to pot metal) which does not stand the rigors of time well.  It tends to absorb moisture then develop splits or cracks.  This can get so bad that the unit become unusable.  I had this problem on an original 1916 Indian Powerplus a few years ago.  I searched all over for a good Dixie or just a good base.  Eventually I found one but only after seeing many with cracked bases.
    For an excellent, in-depth discussion of the Dixie and its operation check out Paul Alting Van Geusau's Dixie web page.

Splitdorf Dixie mageto parts list
The Aero is a further development of the Dixie.  Its appearance is very similar but with more distinct bulges on its sides. It was used on the new Indian Scout in 1920.

Model S
    The model S appeared around late 1922 and continued in production until 1928.  It is an inductor type high tension magneto with an aluminum base and one piece steel rotor shaft.  The model S was made in a variety of motorcycle configurations including single cylinder (S-1), V-twin (S-2) and Four cylinder (S-4).  As a side note, in my collection I have a very unusual 3 cylinder aircraft version as well.  Unfortunately I don't know its specific application.  The model S is easily identified by the "Model -S" cast into its base and the steel wire bail used to retain the distributor cap.  Further variations of each type are identified by a small brass tag on the side. Two examples are  S2-1604 = Right hand rotation - 45 degree firing, S2-1611= Left hand rotation - 42 degree firing

Model NS
    This model is a further development of the model S.  It came into use in early 1928 and continued until 1932 or 1933.  Identification of this model can be confusing thanks to Splitdorf's use of the same base casting as the model S.  As described above, "Model - S" is cast into the base.  These were made in 2 cylinder (NS-2) and 4 cylinder (NS-4) versions.  An NS can be easily identified by the spring clips that retain the distributor cap instead of the wire bail used on the model S.  Specific applications are identified by the small brass tag on the side; NS2-2522=Right hand rotation-42 degree firing (Indian twin), NS2-2524=Right hand rotation-45 degree firing (Excelsior twin), NS4-2588=Left hand rotation (Indian Four), NS4-2586=Right hand rotation (Excelsior-Henderson).

Splitdorf NS magneto parts


Model CD

    The model C and CD came into use following the NS in the early 1930s.  It was $10-$20 option available during the depression era when production costs forced Indian to make the lower cost distributor ignition standard.

Model CDH parts list

Excerpts from the a model CD owners manual

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