Alternative methods for making tapered headers

[Dvsrd]

Hi,
I have mentioned in earlier posts that I am less than happy with a pair of stainless Higgspeed exhausts I got for my RD350A. One of my complaints are the apparently oversized headpipes, which I would like to taper.
The straight header section, approx 120 mm from exhaust port is quite straightforward to fix, either by machining tapered sections from thick wall SS hydraulic tubing, or by cutting out a wedge, squeeze the pipe shut over a tapered mandrel, and re-weld.
The bent part is where I may encounter problems. Making pie cut sections of a straight tapered pipe is one way, hydroforming a new section is another, and cutting out a wedge, like described for the straight section is the third.
Any suggestions or recommendations on what would be the easiest way? The taper will be quite moderate, maybe 1 degree. Note that the material will be SS, so not the easiest to hydroform I guess....

[rodneya]

Ezin Hobeki has a free cone designer and CAD viewer that can be used to design the coned sections to make a tapered header to suite your specs.


Under downloadshttp://ypvsbox.free.fr/