This is just a curious question, triggered by me seeing some army surplus 3 phase 5kw generators on youtube. Apparently they give you (3) 120V legs each at 120 degrees, so if you need 120V single phase then no problem, just use one leg. But assume you want 240V. You can use a step-up transformer on a single leg, or you can use 2 legs and get 208V (because the 2 legs are 120 degrees out of phase). But say you want 240V and you want to use 2 legs for more power. What would it take to shift one leg by 70 degrees while maintaining 120V?