take a cylinder and cut it in half... so you get a 180 degree 2" radius bend (4" diameter) Looking for 1/8" aluminum preferrably.

I found some extruded 1/4" aluminum "D-shape" from Ross machine Racing...but I have to cut it up to weld it on the inside...anyoen have any suggestions?

Also...i plan to flange my plenum so it can be taken off to be ported by someone else.

 

cut a piece of 4inch tube down the middle ???

 

I'm guessing that you don't have a bandsaw?

 

I can cut it myself...its just a real bitch. If I could buy it pre done...and PERFECTLY cut I would save a lot of time.