Exhaust tubing

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Exhaust tubing

Postby geofff » Thu Sep 05, 2019 9:15 am

geofff
 
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Re: Exhaust tubing

Postby Martin Kemp » Thu Sep 05, 2019 10:30 am

I am boycotting Amazon, but as to the pipe bender, I have one of those but it is no use for exhaust tubing. It will just fold thin wall tubing in half.
I use a much more expensive external mandrel bender but that will only bend tubing 16 swg or thicker and with a minimum radius of 5" which is a bit on the large size. It is OK for making about 10 off systems and for roll hoops but too expensive for one exhaust system. The cheapest and easiest way to make a 1 off bespoke system is to buy pre-made bends which are available from competition exhaust specialists and weld them up yourself. TIG brazing is an easy way of joining up the bends. I would go for mild steel as it is cheaper,easier to work with, and you will probably modify or replace the system long before it rusts away.

I don't know about the swaging tool it looks quite handy and good value - if it works

Martin
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Re: Exhaust tubing

Postby geofff » Thu Sep 05, 2019 1:37 pm

Hi Martin,

So exhaust tubing is normally 18SWG? And those types of bender would just cause the inner bend to crimp? Even if I applied heat prior to bending?

Apologies for questioning, I just hate the idea of mail ordering (and probably missing something). Would you mock up a system with toilet rolls to make certain of design / fitment beforehand?

I know mild steel weighs less than stainless, not to mention giving off less nasty gases when brazed / welded. I've done an MMA welding course and have a mate of mine lined up for some TIG lessons so hopefully got that side of things covered.

Ta

Geoff
:)
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Re: Exhaust tubing

Postby Martin Kemp » Thu Sep 05, 2019 6:10 pm

My exhausts headers are 1.5" 16 swg but I would make them 18swg if I could. 16 swg does have the advantage that the next size down tubing will sleeve inside it. I doubt if that bender would work even with heat -as you say it will just crimp the tube - unless it is very thick wall tubing.

You could try packing the tube with sand but I haven't ever been able to make that method work. I have also tried low melting point alloy inside the tube but that didn't work well either.

For mocking up the system I would use foam pipe insulation or you could use flat cardboard cutouts with taped-on ribs to represent the other plane

Martin
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Re: Exhaust tubing

Postby F1300Tony » Thu Sep 05, 2019 7:49 pm

Why not buy ready-made bends and weld them together? This can be done very neatly.
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Re: Exhaust tubing

Postby Gloves » Thu Sep 05, 2019 10:05 pm

I built my exhaust from mild steel bends from Custom Chrome in Nuneaton. I used 1/2 inch dia aluminium wire covered with foam insulation to work out the pipe runs then took them to CC to create the custom bends. I recieved a box of unidentified bends back which gave me a challenging but very rewarding 3d jigsaw to TIG weld together. Hard work but very rewarding. Its been on the car for nearly seven seasons and is still going strong.

Mark
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Re: Exhaust tubing

Postby geofff » Fri Sep 06, 2019 8:24 am

Fair enough. With so much accumulated experience telling me the way to go....... I'll follow the advice.

Ta

Geoff
:)
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