V12 zoomie headers - how do I?

[Jantrix]

Headers are holding back a build. I need to build a set of zoomie style headers for an Allison V12. Dual port exhaust so 12 tubes per side, exactly the same. Nothing fancy, just 12 down tubes that hook a the bottom like a funny car. I might combine the dual ports, and do six per side. What I really need is advice on what material should I use, what method of bending? 

This is the project. Been sitting tooo long.

 

Edited April 9, 2022 by Jantrix

[Ace-Garageguy]

 

If you really want curved zoomies, you can make a bunch of identical bends by tightly wrapping styrene rod around a dowel, securing the ends, and dipping the whole thing in boiling water for 10 or 15 seconds to set the curve, then in cold to temper the plastic. Allow it to cool, and cut it into appropriate sections. Then drill 1/16 or so into the open ends.

For much less effort, it may be possible to get a perfectly functional looking exhaust setup using straight styrene rod, drilled on the ends...something like what I did on this one.

[NOBLNG]

You could try copper?

http://www.modelcarsmag.com/forums/topic/167575-building-exhaust-headers-from-copper/#comment-2545863

[Fat Brian]

I need the exact same thing for a build I'm planning. My plan so far is to build a jig out of wood that will give me consistent bends. I was planning on using thin stainless steel tubing with a brass rod inserted where the bend is to keep it from collapsing but Molotow looks good enough that I might stick with plastic for ease of assembly. 

[Plowboy]

I think in this particular case, I would use solder (non rosin core). Once bent, drill out the end, polish and install.

Edited April 9, 2022 by Plowboy

[GLMFAA1]

To get that many pipes use the Tommy Ivo 4 engine dragster. The Allison engine exhausts weren't that large.

greg

 

[Fat Brian]

  On 4/9/2022 at 3:32 PM, Plowboy said:

I think in this particular case, I would use solder (non rosin core). Once bent, drill out the end, polish and install.

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I thought about that too, or soft aluminum jewelry wire. I still need to find someone to make the decals so I haven't gotten serious about figuring out the headers yet.

[Jantrix]

  On 4/9/2022 at 1:21 PM, Ace-Garageguy said:

If you really want curved zoomies, you can make a bunch of identical bends by tightly wrapping styrene rod around a dowel, securing the ends, and dipping the whole thing in boiling water for 10 or 15 seconds to set the curve, then in cold to temper the plastic. Allow it to cool, and cut it into appropriate sections. Then drill 1/16 or so into the open ends.

For much less effort, it may be possible to get a perfectly functional looking exhaust setup using straight styrene rod, drilled on the ends...something like what I did on this one.

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That's what I was thinking about too. But getting each bend perfect, and matching on each one seems a long shot. I want these headers to be a focal point in the build, so I really want the upturned end.

  On 4/9/2022 at 1:41 PM, NOBLNG said:

You could try copper?

http://www.modelcarsmag.com/forums/topic/167575-building-exhaust-headers-from-copper/#comment-2545863

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How easy is it to get a length perfectly straight? I haven't looked at this yet.

  On 4/9/2022 at 3:32 PM, Plowboy said:

I think in this particular case, I would use solder (non rosin core). Once bent, drill out the end, polish and install.

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I've seen folks use solder for headers in the diameter I'm going to need, and they tend to sag over time. 

 

Thanks for the input guys. Greg, I'd never part out a kit that cool. 

[Draggon]

Plastruct sells bends in various sizes and degrees that are pinned at both ends which would be perfect. Their website is not the easiest to navigate, but this link might get you started. I've long wondered why folks don't use these to build headers, since you could assemble them just like they do in 1:1.

https://www.plastruct.com/search?q=bend

[Ace-Garageguy]

  On 4/10/2022 at 5:46 PM, Draggon said:

Plastruct sells bends in various sizes and degrees that are pinned at both ends which would be perfect. Their website is not the easiest to navigate, but this link might get you started. I've long wondered why folks don't use these to build headers, since you could assemble them just like they do in 1:1.

https://www.plastruct.com/search?q=bend

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THANKS !!   I didn't realize they still sold those (of course, I never looked).

My father used to bring me odd sizes from time to time, leftovers from developing piping runs in the days way before CAD.

[tbill]

They also have butyl (sp?) covered wire, although not sure if they have large enough diameter for headers.

[Jantrix]

  On 4/10/2022 at 5:46 PM, Draggon said:

Plastruct sells bends in various sizes and degrees that are pinned at both ends which would be perfect. Their website is not the easiest to navigate, but this link might get you started. I've long wondered why folks don't use these to build headers, since you could assemble them just like they do in 1:1.

https://www.plastruct.com/search?q=bend

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Thanks, that might be the way to go.

[mr moto]

  On 4/11/2022 at 4:37 PM, tbill said:

They also have butyl (sp?) covered wire, although not sure if they have large enough diameter for headers.

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I've tried the covered wire before since the LHS had some in stock. Great idea but not as good in practice. I find it very stiff and difficult to work with. Any use of tools to bend it will damage the relatively thin and soft covering.

LHS doesn't stock the bends and I didn't know they existed but that looks like a much better idea to me.

BTW, I feel lucky to have a LHS even if they don't always have the most advanced stuff.

[roadhawg]

I know I tend to underthink things and look for the easy way out, but why not simply use two sets of funny car headers? You would probably have to make the flange where they attach to the heads, but all the lengths and bends would be the same. 

[Jantrix]

  On 4/16/2022 at 12:38 PM, roadhawg said:

I know I tend to underthink things and look for the easy way out, but why not simply use two sets of funny car headers? You would probably have to make the flange where they attach to the heads, but all the lengths and bends would be the same. 

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Tommy, each of the 12 cylinders has two exhaust ports. So it would be six downtubes with a Y at the mounting end, or 12 individual downtube, per side. However, I need to thank you for replying.  As, when I did a Google search for that image show you, I accidently found some 1/25 3D printed Allison headers. Not exactly what I'm looking for but clearly there are options I hadn't researched yet. 

Edited April 21, 2022 by Jantrix

[Mr. Metallic]

  On 4/10/2022 at 3:08 AM, Jantrix said:

 

I've seen folks use solder for headers in the diameter I'm going to need, and they tend to sag over time. 

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I've never heard of a sagging issue with solder. Not saying you're wrong, I've just never heard or witnessed that happening. 

[Jantrix]

  On 4/21/2022 at 6:53 PM, Mr. Metallic said:

I've never heard of a sagging issue with solder. Not saying you're wrong, I've just never heard or witnessed that happening. 

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I saw it once on a model at a contest. It was a classic Hooker type, 4 into 1. The builder said he should have added a support like an exhaust bracket. It was the only time I've seen it, admittedly. 

[dartman]

Late to the party but I have used used plastic tube with wire inside for shapes.....