First it is "torque converter" not torque convertor.
The idea seems feasible, providing there is some disengage mechanism so you can change gears; you might do some more research - Googleing "torque converter" yields 1.2 million sites among them,
Howstuffworks "How Torque Converters Work"
and
Automatic Transmissions: What Makes Them Work
But a torque converter seems a bit heavy; one might consider a centrifugal clutch if one can be made to disengage to change gears. But one thing a manual mechanical clutch has in its favor is that you can disengage at any speed, which to me, is a safety feature in the event there is a throttle hang up. Note there are periodic news reports of cars "going out of control" and taking out pedestrians and or store fronts, etc. I'd bet there has been very few such incidents involving manual transmissions.