Electric motor timing basics for brushed motors:
More timing ( 15* - 35*) = more HP and better RPM but this will also wear out the brushes faster and reduce the lower RPM torque
Less timing (5*- 15*) = More toque and accelerate quicker from stop but will cost a little top speed and the brushes will last longer compared to more timing.
When using the same motor and only changing the timing it will affect the acceleration drastically in certain circumstances. This will ussually require a gear change, ussually 1 tooth smaller spur for less timing and ussually 1 tooth less on the pinion for more timing. In offroad truck I always prefered to run 10-15 degrees, buggy I liked 15-20 degrees, and when I did run 4wd it was 5 -10 degreed of timing, for this allowed the brushes to last a lot longer. You do not need to concern yourself with trying to adjust timing for the motor to reach a certain temp, you use this to help adjust how the motor performs(you want more rpm or more accel. No matter what I always tried to keep my motors as cool as possible no matter what.