I hate to sound dumb, but just what is a "divided plenum" on am inline six, with or without siamesed intake ports?
With respect to the plenum volume, is there a good "rule" for plenum volume for a given engine displacement and RPM range? Tomorrow I will measure the volume in the five-carb manifold that I am using on my 278-cu. in. 261. I was just looking at an intake manifold design book where the authors showed results with a very large plenum where the actual flow rate (or volumetric eficiency) would actually decrerase as rpm increased at some rpm ranges.
