But the real question is why settle for 400 cubes.
Bigger cubes is better at everything.
When Jesus comes back...check out what he has, 3500 cubic inch 100-71 blown nitro HEMI
10 inch bore 5.6 inch stroke, yeah you better believe it.
How much effect does the almost 1.3 sq/in in area of the piston come into play wrt a 4 vs 4.2" bore? it's almost 10% more surface to push down so I'd have to think that has some impact. if so, how much?
This is an unanswerable question due to the near endless amount of combinations. If you tested this idea at the same cubic inch then you would also have to try the various strokes. Then there is every part of the engine that has to match and then every part of the engine that can be replaced with another part to try.
So, having a many different cranks, rods, journal sizes, pin sizes, piston variations, camshafts, bearings, don’t forget the roller cam bearings, piston ring packs…….. every part changeable on the engine would need to be compared.
But this thread is about "hypothetical" or the perfect engine, and preferences to the builder. We obviously can throw in real engines for comparison of all makes.