i would think it would be more complicated than that. If you think aboutthe engine in its entirety, there is more than one intake valve open at any particular time. I dont have it charted out but the ol 18436572 tells me that when 1 is open, 2 and 8 may be open (either just closing or just opening) but is different amounts. so when i is flowing its max, part of the intake charge is going into other cylinders which may be just closing or just opening.

so the flow is proportional to the amoutn the valve is open and where the piston is.

so using differential equations to set up the dynamics of the engine would be required to determine the answer.

And what that answer is, I cant tell you because Im not about to go trying to figure it out.

I just thought Id add a little more difficutly to the problem.