If they are identical to the NIR class 4000 (apart from the track gauge) then it would be a MTU 6H1800R83 engine per car with a ZF Ecomat-Rail 6 speed hydro-mechanical drive similar to those on the class 172s.
In this video you can hear the gear changes quite distinctly.
That engine is 530hp, which seems way overpowered for what will be largely commuter and secondary line duties, Pennine hills notwithstanding. That however seems the norm these days.