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MSFS20 Cylinder displacement mishandled by the Aircraft Editor in the current SDK?

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If I in the Aircraft Editor, as an experiment, enter a cylinder displacement (per cylinder) of 50 cubic inches, and four cylinders, and choose File>Save, the value for cylinder_displacement in the engines.cfg is written as 172800... That value should be the same per-cylinder displacement. (As can be seen for instance in the Cessna C152's engines.cfg, which has 58.3, which times four indeed gives 233, the total displacement of its O-235 engine.)

Needless to say, this makes using the Aircraft Editor slightly pointless, if you will have to manually edit the engines.cfg after each save anyway. Otherwise your engine(s) will be ridiculously over-powered with amusing results.

Is there something I am missing? Could it be that I have some other setting very wrong that affects this?

Edit: Ah! I now see that this has been mentioned here already in August, in https://www.fsdeveloper.com/forum/threads/aircraft-editor-cylinder-dispacement.448600/ . So the value you edit in the Aircraft Editor needs to be in cubic feet... Asobo getting non-metric units mixed up I guess.
 
Anyway, let me mis-use this same thread to ask some follow-up questions then: Apparently MSFS calculates the engine power (hp) and RPM based on the cylinder displacement, compression ratio, number of cylinders, and what else? (And ignores the specified max_rated_rpm and max_rated_hp.) I.e. what should I tweak so that I end up with something close to the expected power and RPM for max throttle? I'd prefer not to touch the fallback power_scalar, that seems like cheating;)

The engine I am using is the Curtiss V-1570 from 1930, 12 cylinders of 129 cubic inches each. The nominal RPM should be 2400 and the power output 600 hp.
 
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