What you're saying is that you've got more volume in the combustion chamber (correct) but the same swept volume (incorrect) this is impossible with a fixed length con-rod/crankshaft, You cannot gain in one area and remain constant in another.
Swept volume always remains the same unless you alter either the stroke or the bore. By swept volume I mean the cubic capacity of the engine, ie the CSA of the bore multiplied by the stroke. So yes you surely can gain in one area and remain constant in the other?
You appear to have neglected the combustion chamber volume increase in your calculations, in your second calculation your combustion chamber volume remains at 50,000mm3. But how can it remain the same if your con rod has changed length?
