That large capacity two stroke V uses a very unusual engine configuration with opposed pistons IIRC and has an interesting history. The design is based on work done in WW2 to develop an engine for motor torpedo boats - MTBs. The Royal Navy wanted super-fast patrol boats to counter the German E-boats which were raiding Allied shipping in the Channel.I loved those old loco's as well Raymond, They looked so huge and powerful when I was a lad. Didn't know they were two stroke!
This is all half-remembered stuff from many years ago and I might be talking complete rubbish . . .