Thought I'd show a couple of pics of the headers I've been cobbling together.

I'm a bit concerned about them cracking, as other builders seem to have had problems with that happening. My headers are particularly complex, so have lots of welded joints. As I've used MIG, each weld has needed some dressing to get a smooth joint - so the wall thickness around each weld probably varies quite a lot too.

So... two questions: Where am I likely to see cracks appearing, and what can I do to strengthen the headers to prevent the cracking before it happens?


Headers2


Headers4

Between the flange and the pipes is the first port of call. It looks good what you have done, and it will ruin the looks, but you need strip to spread the load out. A few strips from the flange to 50 - 75mm along the pipe.

Darren

[Edited on 23/3/10 by turbodisplay]

More importantly when you get it right how much would you charge me for a set? I am building a V8 and will need exhausts in the future. hehe

How about adding a brace to the end of the header that goes back to the engine so there is no movement fighting the header? Then use somekind of flexi joint between the header and rest of the exhaust

Nice job by the way!!

[Edited on 23/3/10 by MK9R]

that is amazing!

What material is it all made from?

If its ALL stainless, is it all the same grade?

Are there any Ordinary steel to Stainless welds?

Did you use the correct filler rod for the materials being welded (even for the stainless joints)?

I ask, as if you weld ordinary steel to Stainless and use the wrong filler rods, then you get embrittlement, as it makes it very hard, and will then crack with the stress (ie getting hot and cold as its an exhaust).

I am no expert, but I know this is the case for dissimilar metal welding, especially stainless and ordinary steel.
(I was thinking of the flanges, as they look like ordinary steel)

I would ask 907, as he is the expert on these matters.

Other than that it looks good.. a nice job.

Thanks for the positive feedback! The headers certainly took a lot of effort to create, which is why I don't want them to break after a few hundred miles of action.

Re material, the tube is 304 stainless, the flanges are mild steel, recycled from an old set of headers. All welded with stainless wire - I think 308 grade, though not 100% sure as it doesn't say on the pack.

Flange->pipe joints can be improved as per turbodisplay's suggestion. Anything else?

The idea of bracing the end of the header is interesting but might be a bit difficult to engineer.

[Edited on 23/3/10 by AdamR]

Thats really well done - especially considering your using a MIG.

You could put some spot welds were the pipes cross each other, will tend to keep the flanges supported, might not look pretty though.

Extremely well done - they look superb