No Replacement for Displacement (myth or fact)

Its Fact - the engine is an air pump,,,more air and fuel you can circulate through the more power you can obtain.

Yes the more fuel and air in a certain amout of time (rpm) makes horsepower, say we build a 273 and a 546 and the 273 would have to spin twice as fast as the 546 since its half the size but it would have the potential to pump the same amount of air in the same amount of time (displacement X rpm = hp) .