exhaust header collector help

[dustbull]

Hello everyone, this is my first on here so here it goes:
Im trying to make an LS1 header to learn some of the 3d rendering features. Heres what i have so far, and what i need to do:


I need to make that triangular/pyramid insert (above) and dont know how to go about doing so. (hope my intentions of its design are clear enough) Can anyone give me any tips? Thanks in advance!

[MikeScott]

make a 3d cone, then subtract solid cylinders from it to get the shape?

[Dana W]

Does it have to be for an LS1? I need a set to fit my 4.6 liter Mustang GT engine but you're gonna have to twist 'em down a little to clear my steering shaft.

I have actually seen a number of those things, but I only have ACAD LT so I cannot illustrate in 3D.

The real ones have the straight lengths of header tubes touching, or almost, along their length. Then the mouth of the collector is slid over them and welded in place. Some of them are crimped into the hollows between the header tubes. The outside tapered part of the collector is made up of sections of tube cut to converge at the diameter of the end fitting that meets the header pipe from the exhaust line.

That inside piece that you show will only need to be 4 half sections of cone turned convex side out. Some of the header mfg's don't even use that inner cone piece. The better ones do.

[Dana W]

Here's a couple of photos, but they don't show that inner cone spikey thingy. Of course your drawing is for a RACE car so you won't need all those curvey swervy tubes to clear all the parts that make it street legal.

[ReMark]

dustbull: Take a look at the LOFT command.

[ReMark]

Loft example.

Two profiles (on far left) were used to create the tapered object. The smaller of the two is half the size of the larger. I've provided two views just for clarity purposes.

Tapered shape.jpg

[Coosbaylumber]

Back when I tried to do same as Dana did for a simple older four cyclider taken to Bonneville. Boy that only looks easy, but really takes time to complete.

Wm.

[Dana W]

Dustbull,

Check out this thread from the "Similar Threads" list below...
http://www.cadtutor.net/forum/showthread.php?t=29321

[Dana W]

Not being able to draw in 3D, nor even knowing the correct terms is certainly a handicap to me. At this point I may be a handicap to Dustbull, but I only jumped in cuz I thought I knew my way around a set of headers.

I want to describe how the header would actually be constructed in order to give him more ideas on how to draw it, and I don't feel like I am having much luck.

The pipe jockey's down at Whoosit's Headers build that little cone thingy out of header tube. They weld 4 pieces together in a square bunch, then baloney slice each pipe diagonally with a plasma cutter. They end up about 3" long and appear to be 4 half cones welded together along the convex side with the inside facing out.

Coosbaylumber - Back when I tried to do same as Dana did for a simple older four cyclider taken to Bonneville. Boy that only looks easy, but really takes time to complete.

Coosbay... No, wait. I don't build headers. I just bought some shorties a year ago for my mid-life crisis vehicle. It's a 2007 Mustang GT in Arrestmeofficer Red. It took me two full weeks to get them boogers on there.

[dustbull]

Thanks everyone for the help! I just had to change my initial drawing a bit before lofting it and it worked great! to make it a bit more realistic i then shelled it so the material is the same thickness as the tubing.

This has to be something simple that i hope to figure out on my own, but i just need to attach the pyramid into the middle of the four tubes, how would i rotate it around and such and then place it in there?