Based on what I heard last week in an RCTS meeting -
see my post 685 above - I think they are still using the Ford engine (as there was no mention of using anything else).
Their Chief Engineer said the Ford engine itself had been fine, it was the stuff around it and the design of the genset units that has been the cause of most of the reliability problems e.g. the radiators getting blocked with pollen too easily (now replaced with a different design), the hot parts not being sufficiently insulated or separated enough from other parts etc. I think they're now on version 3 of the genset unit design (first version was designed by an outside supplier, the latter two in-house).