[AT] Magnetoes

[Gene Dotson]

    Most magnetoes were standardized in 1939. Prior to this, many 
manufacturers had their own magnetoes and mounting system. The industry 
standardized magnetoes to 3 commom types of mounting and operating system. 
The common flange mount is available with gear drive and the cross tang 
drive. The base mount was either shaft or cross tang drive. The magnetoes 
are virtually interchangable between engines with the same number of 
cylinders and drive arrangement. The primary difference is in lag angle for 
starting, which with most tractors is not that much different and can be 
changed. Rotation can be changed by reversing the direction of the impulse 
coupling spring and aligning the rotor drive gear.
    During WW11, Case tractors could have come from the factory with any of 
5 different magnetoes. Virtually all of the Case magneto production was 
devoted to building magnetoes for aircraft engines, so to keep the tractor 
lines running they bought mags from Faribanks-Morse, Wico, IHC and Bosch. My 
1944 Case S has a IHC magneto from the factory.

                        Gene