Upgrade 5 pole core motor for Hornby locos. This option has the more powerful magnets, and therefore produces a lot more torque. This is just the core motor, and you will need to re-use your own existing worm gears or flywheels.
Hornby 5 Pole Motor
Hornby 5 Pole Motor Upgrade for Class 395, Eurostar, Railroad 43 & Pendolino