Bit of flawed logic there from Darin. If two engines have the same capacity [ cu in ], but one is short stroke/big bore, other is small bore/big stroke, the contact area of the rings against the bore is the same for each engine. The big bore does not have an advantage because of the bore size.
He didn't say anything about total surface area, maybe going further up and down the bore has more frictional hp loss than the contact area of the rings on a larger bore ?