No one ever heard of such 240t before Long's presentation though
This 240t engine has a equally long history of rumor as YF-135 many years ago before 9ispace.cn was shutdown. Some members here were regular visitors of that website including myself, and I learnt it from there.
and don't make sense if you have a two-chamber 500t and one-chamber 240t in parallel development.
But does it make any sense to have a one-chamber 360t YF-135 in parallel?
BTW YF-130 is 480t in spec (100% thrust at sea level), usually engines will be running at 110% at some time, so maximum 528t. The 500t is just a general name for the class, same as YF-100 is at 120t but always called 100t class. So there is no special difference between 240t and YF-135 other than the former using the same combustion chamber of YF-130.
This kind of parallel development is very usual in the past decade or more, my own company would develop a baseline product for world market and there will be parallel teams in smaller sizes working on market adaptations for markets large enough for special attentions. Those parallel teams are closely connected to the main team, they only work on the differences and their product releases are almost at the same time as the main team.
