Intake manifold design

[mitch_04]

I've always thought it'd be interesting to build my own intake manifold. I have a 3.5L inline 5 out of a '05 Colorado that maybe my test engine. I've noticed most sheet metal intakes are built with a rectangular main section and the runners are cylinders. Is there a reason for this?

Also, why don't people manufacture an intake manifold similar to a reverse header? As in having equal length runners meeting up at a collector, then having the throttle body mount onto the collector?



Would love to get a good thread going on this!