[Joe Johnson]

You can clearly have more than 8 motors.

My understanding is that you can use all the motors that are in the kit:

3 Bosch Drill (in fact a Johnson Electric motor)
2 Chiaphua
2 Fisher Price (in fact a Mabuchi motor)
1 Mabuchi
2 Globes
1 Johnson Electric
2 Keyang
2 Jideco
1 "Torque Motor"
=============
Total 16

If you think about it, there are even more motors in the kit but you can't use them to get shaft work out of them (the fans, the pump, the beacon light motor, etc.)

Joe J.