Motor swapping, timing issues

[Nicholai Teslot]

I have an old Parma Womp. It is the home track version. I have replaced the motor with a newer, very hot, 501 . Now here is the problem. The home track motor has the pinion on the endbell side. The 501, on the can side. Now to get the car to run in the right direction, I have had to reverse polarity. I lose what seems to be about 2-5 k rpm. This leads me to believe the motors arm is timed. So what to do ? Can flipping the motor work ?

[Modlerbob]

If it is a standard womp flip the crown gear to the other side and reverse the motor leads, then the motor will run in the faster direction

[bill from nh]

The 501 needs the crown gear to be on the right side of the pinion. The armatures in these 501 motors are timed 15-20 degrees. I assume the home track motor used the crown gear on the left side of the pinion. If so, when you reversed the polarity on the 501, you retarded its timing by some 15-20 degrees. The motor runs slower & hotter in a situation like that.

In addition to the 501 having a hotter armature than the home set motor, it has stronger magnets too, which should result in better braking. The 501 will also draw more power than the home set motors.

[slothead]

Question - do you intend to use this car at home or on a large commercial or club track? Many of the home racing folks here prefer less 'hot' motors so the cars handle better.

I had a bunch of Womps left over from commercial track days and have pulled the motors when re-purposing the chassis for use on my oval at home. I now run the track on 11.4 volts and really enjoy mild motors and manageable, more realistic speeds. Back in the 80's guys would beg the guy behind the counter at the commercial track to crank the power supply up to 18v, which sounds crazy to me now.

[Nicholai Teslot]

Thank you all for the responses. I flipped the crown gear, now it runs great.