SBM Edelbrock/Speedmaster Head Data

I agree with your conclusions that mathematical equations cannot totally define and predict what is happening in an engine.

But what the math does do is to help give a deeper understanding of the cause and effect of anything. If we can write an equation that approximates something we see in nature, we can look at each individual variable in the equation and see how it effects the whole system.

Case in point is the port size. If the energy of the moving air/fuel mixture can be represented by an equation similar to KE=1/2m*v*v, where KE=kinetic energy, m=mass and v=velocity, we can understand that the velocity of the mixture has a much greater effect on the port energy that the mass of the mixture. That's one reason why velocity is so important. It doesn't matter that the equation is 100% correct, because it is not. But the relationship of the variables is pretty accurate.

Here's one I want to know: In the equation for cfm demand where Cfm=(cid x rpm x 0.0009875)/(# of cylinders), we all know what cid, rpm and # of cylinders are. Where does the 0.0009875 come from? If we knew that answer and understood it, another level of understanding would be opened to us.