Header Fabrication

Howard Jones

Supporter
Now THAT"S a good idea!!!!!!!!!! How about making this a sticky thread or whatever its called? Lots of really good header building stuff here for a first time builder like us.
 
Ron:
I have done quite a few headers and as was mentioned stainless is the way to go.
Also I cant mention strongly enough that fit-up is critical as well as back purging...both mentioned previously but probably done incorrectly the two biggest mistakes when fabbing a header.
I used to do quite a bit of sanitary work for food processing and we would get an inside finish as good as the outside...no occlusions or craters inside to collect particles and prevent proper cleaning.
The weld should have a slight hump both outside and in and you should be able to weld without filler rod if the fit is correct.
Also I am attaching a couple of photos of the purging setup I use...saves a lot of gas and time and works well.
I made these but I am sure something is available online..if not let me know I have extras.
Cheers
Phil
 

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Nice puddles, your friend knows how to weld!

Yep he builds F1 systems and most of his work is Inconel , he thinks he is slumming it when I get him to knock up things in stainless.

Inside of the collector is as neat as the outside :)



Here is a system on the car we built for him.

 
When I made the headers for my 289 in a Cobra I wanted to create some primary tube length to maintain or generate torque
12386picture_052__2_.jpg

I used a Belt/Disc sander (manditory for proper fit after cuting) and many .035 thick cut off wheels in a 6" hand held Milwaukee grinder instead of a band saw. It is very time consuming, dirty, but VERY satisfying. They work very well and sound fantastic. 1 5/8 t180 degree bends and a few short lengths of straight tubing. After coating they look very good.
 
When I made the headers for my 289 in a Cobra I wanted to create some primary tube length to maintain or generate torque
12386picture_052__2_.jpg

I used a Belt/Disc sander (manditory for proper fit after cuting) and many .035 thick cut off wheels in a 6" hand held Milwaukee grinder instead of a band saw. It is very time consuming, dirty, but VERY satisfying. They work very well and sound fantastic. 1 5/8 t180 degree bends and a few short lengths of straight tubing. After coating they look very good.

You have to love some of the stuff that goes on here. Cracking job.:thumbsup:

Bob
 
As others have said, by the time you ceramic coat mild, you're in the same ball park as stainless. Ace Stainless and Verocious motorsports are my favorite suppliers for stainless tubing and sanitary style bends. They're 10x nicer to work with over traditional mandrel bends. Once you use them, you'll never go back.

Use the biggest gas lens you can get your hands on, I like a #15. Pick up a gold shade 9 lens while you're at the welding store. The difference is incredible. Take your time and make absolutely sure you have zero gap in your joints, clean them inside and outside with scotch brite and acetone before welding. I put a long sharp point on my tungsten for welding SS tube, I find it helps keep the arc from wandering when working with low amps. Make sure to always backpurge with around ~25 cfh flow of argon as a minimum. Let the tube fill for a few minutes before starting to weld.

My suggestion is to bolt your flanges on and then mount your mufflers/collectors. Once you have a destination, start running tubes.

It takes alot of patience but when done right, they're a functional work of art. This is a set I recently finished for a 427 BBF.







 
Some great suggestions. I would only add that it can be good to have bends of various center line radii so that you can get some tight bends as well as some gentler ones. It can make the system look a little less mechanical and more organic. It also can allow you to make less joins which is good for me as I'm inherently lazy!

However it probably does nothing for performance!

On performance I was advised that if I wanted power at high RPM with my engine (which will rev to 7.5K to 8K) I had to ditch the cross over and have the shortest equal length system possible. This resulted in my setup with a H-pipe. Burns Stainless did analysis and advised this. I built this system below. It is my first attempt at headers with some help from RF.

GT40-Engine-Coyote-1.jpg



GT40-Engine-Coyote-2.jpg


It just takes hours and I also had a big disc sander that faced all the tubes. I actually cut all the tubes by hand with a hacksaw. As it was very thin tube it was easy, controlled and did not create a load of dusty crap in the workshop.
 
Here are my pipes, self made in mild steel with black exhaust pipe paint..a bit ghetto compared to some above but do the job fine. I still need to linish the mig welds back a bit more to smooth off.

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To bring my 2 cents to the subject , these are the headers I made for my 302/331 SBF on a scratchbuilt GT40 ; from this first experience I keep in mind the following main points :

*SS 304 ( 1.6 to 2 mm thick) with pre-fabricated bends is a very valuable solution.
Needs some patience, but you know you will get at the end ...

*One independant flange for each cylinder ( 8 mm thick SS) is a must for a cross-over system ; the main point is to memorize the right de-installation and re-installation sequence!

*4/1 own merges are a satisfaction, but a huge work !

*A seen on the pictures, the pipes color is evoluting to some brown from usage ...
 

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Terry Oxandale

Skinny Man
I recently tried a product called Solar Flux to avoid the back-purge complexities of welding stainless. I was surprised how well it worked in my application. Very simple to mix with HEET methanol-based gas-line antifreeze.
 
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