How to improve airflow here?

[427dart]

This is a picture of the Cylinder #6 intake runner/plenum entrance. The floor of that plenum area is the roof of lower level which congest the area due to height of the intake runner layout.
I ground some material from the top of the plenum area to open it up but you are limited due to wall thickness where carb pad meets runner.
Would it be worth the effort to add weld to the outside area where the runner meets the carb pad to raise the inside of runner roof for a better line of sight to runner opening?
Looking at plenum and into runner 6 while boring out holes to 1.700


outside view of runner 6 on manifold.


Did as much blending and opening up of runner areas as I felt safe not knowing wall thicknesses and I run 1.5 inch carb 4 hole spacers for more
plenum area. Amazed it still makes around 560 HP @ 5500 with this intake. Runs very strong though.

[Carnut1]

I like the idea of having the holes larger than the throttle bore holes. I would not be afraid to weld and get the flows a bit more even, I would guess there is an easy 15% difference in flow cylinder to cylinder. The wet flow issues can be bad in a design like that. I know you have tuned it to run well so each change will require a fresh tune and jetting you already know that. Have you tested each runner with carbs and air cleaners? A ton of work but will let you know where it needs help. Thanks, Charlie

[BOOT]

You need some radius to turn, many make the mistake of cutting what little there is at the flange, it does appear to have a bit more than some intakes but I'd still just radius it. I'd also widden it like a SSR. If your bore is a bit larger than the throttle plate it could shear fuel at the plate(provided the gasket isn't in the way) and be a slight reversion step.

[mag2555]

One thing to concider here is that the shorter runners in the Manifold will have less port velocity and slower moving air can negotiate tight turns better.
This means that port areas that look like a bad restriction may not be the full on disaster your veiwing of them tells you they are!

Air flow wise getting air to bend around anything tighter then a 15 degree radius will require getting more width in that area .
tipcally using a 15 degree bend somewhere will cost you 20% in flow if the velocity is high enough from what you would have had with direct line of sight.

I would weld in wherever I could on that to ease up on the bends, or to get more area.

[cv67]

A the bottom of a 4 hole plenum or spacer would you all recommend tossing a radius on it or leave the sharp edge to shear that fuel?

[Carnut1]

A the bottom of a 4 hole plenum or spacer would you all recommend tossing a radius on it or leave the sharp edge to shear that fuel?

Radius with texture is what I like.

[mag2555]

To me there is not enough air speed there to make any improvement for better fuel sheering so go with a better radius and like Charlie posted some texture if you can.

What I have done at times when some unknowing folks have gone thru the rediculus effort of polishing the floor of a Plenum is to lay down some epoxy and just when it's about set up press down some very oiled up , very course floor belt sand paper into it , then pull it up to get the much needed texture back on the Plenum floor.