Plenum Volume
Famous bob, I don't think getting the plenum volume in a typical squarebore intake to equal the engine displacement is likely. We have been talking about a tall "tunnel ram" style intake, designed for high rpm operation.
As a quick example, lets say an intake has eight 2.5 inch diameter runners, each 10 inches long. Just those runners alone displace almost 395 cubic inches. If individual runners are not used, the volume grows even more quickly.
The interior volume (total 3 dimensional volume, LxWxH) of the manifold can approach the CID of the engine, and in fuel injected applications, it's even easier to get very large plenum volumes. Look at a current Pro-Stock intake and you'll see what I mean. Here is a pic of John Gaydosh's 2016 Pro Stock intake. It's easy to see how that could be 500 cubic inches.
Famous bob, I don't think getting the plenum volume in a typical squarebore intake to equal the engine displacement is likely. We have been talking about a tall "tunnel ram" style intake, designed for high rpm operation.
As a quick example, lets say an intake has eight 2.5 inch diameter runners, each 10 inches long. Just those runners alone displace almost 395 cubic inches. If individual runners are not used, the volume grows even more quickly.
The interior volume (total 3 dimensional volume, LxWxH) of the manifold can approach the CID of the engine, and in fuel injected applications, it's even easier to get very large plenum volumes. Look at a current Pro-Stock intake and you'll see what I mean. Here is a pic of John Gaydosh's 2016 Pro Stock intake. It's easy to see how that could be 500 cubic inches.