Every one is talking about how this motor or that motor is faster. What legally can you do other than the align the brush hoods (tweaked to get the most timing out of it), soft (hi silver) brushes, heavy springs for more power, lighter springs for more RPM, a nice trued com, and a well shimmed arm to make it go better?
I have heard of some people taking a 4-40 (?) tap to the bushings and threading them to make the shaft have less contact area on the bushings along with making sort of an oil reservoir.
If you cut down the com all the way it should make the timing advance....Right? You would get more brush wrap around and in effect get more timing? How small can you cut an arm before the two brushes are touching the same pole on the arm and making a dead short thereby killing your efficiency? Remember you would have to take in to effect how long it takes to charge the pole on the arm and then figure out how much the arm turned in that amount to time to squeeze it for that much more.