I will be forming some plenums for custom inlet manifolds. I am wondering if anyone has tips or tricks for me to form the aluminum for the plenum. I will be buying sheet aluminum that is 0.125" thick and forming it similar to this shape:



The hardest part I think will be forming the radius at the top of the plenum. I thought pulling the sheet metal over a round tube would be a good way to form it, but I'm having doubts I will be strong enough to do this with my bare hands. How would you do it?

Regards,
Justin

 

Build something to add some leverage to it.

 

wear leahter gloves..and heat it up????

 

Ever thought about buying like a 3-4" alum piping. And cut it in half? There, you will have a nice even round - For the plenium. Then weld on the side walls.

 

make a form out of wood. click my sig.

 

Make sure you anneal the aluminum before you start and re-anneal if needed as you work it. The wood form idea is prolly the best though.

 

it looks stamped from some sort of 20xx or 30xx aluminum, I would build a form from wood and shape it to it

 

why not just buy a cap from somewhere ? its like a half a sphere.....

 

I have to build one for my starion racecar in the NEAR future my idea was to make it from two symetrical pieces but weiRtech way seems more practical

 

your not thinking outside the box. cut teh pipe down the middle for the top, then same size (hole) tube for the tb part. then radius cut some pipe for the tapered end. And then sheet metal for the sides. I have done it numerous times. Just requires lots of polishing and grinding at the end.

 

that's the problem lots of grinding

 

http://myspace.com/antireversionmotorsports

 

I've repaired one of those Virtual Works Supra manifolds after having it be blown up by a nitrous backfire... what fabnewb is suggesting is exactly how that manifold is made.

If you look at the end-cap at the back of the manifold, you'll see where it is 'pie-cut', and the end is made to look nicely radiused. The outside of it (opposite runners) is just a piece of tubing moon-cut in half, and then the top and bottom are plate sections cut and welded in place. It is welded inside and out, and then the welds are ground down on the outside

This would be WAY quicker and more efficient than forming a wood buck, and trying to form that whole thing from flat sheet

 

man i was gonan say, i was afraid after the previous coments people thought i was the only one who did it that way. Forming the proper thickness sheetmetal for a plenum would require either alot of know how, or simply alot of sheet metal tools. sand bag, plannisher, shrinker, english wheel. etc....

 

yeah...the Virtual Works manifold is pieces of pipe and plate pieced together to make that shape...its then ground down and polished. If you look at the piece in the right light you can see every seem where it was welded.

 

you could anneal the aluminum and it would be easier to bend around a round pipe or something to get the shape youre wanting

 

 

Looks nice Randy, but how did you do it?

 

Looks like more than one peice.



See the seam on the bottom of the plenum?