I agree with Marc, going to a VFD can be the best option. This year, I've replaced some rotary phase converters with VFD's for one of my customers. A definite plus was being able to limit starting current & acceleration time. Now, his single phase standby generator can start all his 3 phase motors without having to stage them with time delay relays.

Few things are harder to put up with than the annoyance of a good example.