I had a header break and was wondering about methods to re support it to prevent it from breaking. This one didnt last to long.

I was thinking about adding an additional support at the front of the cannister.

Also was thinking about adding a flex header, not sure if both would be required.

See pictures.

I would guess metal fatigue. Can you install long silicone tubing sections between the engine headers and the mufflers?

Bill

material are too thin I think.

It is metal fatigue for sure. The material is the standard KS gauge. Others mount these successfully so I am intersted to hear of successful installations.

Maybe my mistake is the fixed support at the back and no others so the vibration isnt well controlled.

The metal that KS uses is .4mm thick, A lot thicker than some of the flex headers that are coming out. The flex header I have here from China is .15mm

common problem
The best fix is to always support the ends of the headers using a spruce beam across both headers ,at the silicone/Teflon coupler, then adding tye wraps
It won't burn out.
Secondly
the entire header and pipe/can/muffler assembly should first appear to center it's self before you lock it into position
Failure to do so, is very common .
If you preload the header or the can, be ready for an early failure.

the most easy broken part are that close to the exhaust part. take lot hit and vibration shake. but the end of header tube are not much . can use very thin metal . that's the Idea . the 90 degree part that connect to the flat are 1.2mm . about 3 time thickness than KS uses. make it strong and not easy to broken . compare with aluminium. stainless steel are little difficout to reless the hit , so need quite thickness to build this parts to keep it strong

In addition to (or in place of) the beam joining the headers, would it be usefull to solder a cross tube between the headers joining them (just structurally not the exhaust gas)?

That the mount for the muffler tail end allows some play could be of help.

Adding a support for the end of the header (e.g., with a stainless steel strip mounted onto engine's cylinder head screws) definitely will fix it for all.

The broken header probably can be brazed back with the yellow brazing rod sold by DA + a propane torch.

good advice on supporting the ends of the headers.that will strengthen and isolate them from the flex and vibration of your engine vs. the airframe. Adding a brace between the two will also help.As well as making sure you have some space in the flex coupling between the headers and cans to allow for vibration and flex.
Flex pipes tend to leak between the coils (depending whose it is) and crack easily