Work in progress.
We're building a new set of headers and a fishtail silencer for this V Twin 1000cc.
The owner bought a system from the UK but it was all wrong with the inlet tubes side by side wheras the owner wanted them stacked vertically.
The finishing leaves a little to be desired as well.
BSA V Twin G 12 on work table.
The silencers are cut from a flat sheet of steel.
The flat template is shown along with the 2 halves after partial rolling. A lip has yet to be bent at right angles along the edge.
The 2 halves of the silencer after more shaping with the lip visible along the edge.
They will be polished, as shown in the next pic, before any other assembly.
The louvered/perforated tubes will be inserted as a back pressure and sound control.
Many older bikes had a basic internal baffling design using similar methods
Here the silencer halves have been tig welded together along with the dual inlet tubes and the exit.
Some designs with the side by side entries have one perforated tube baffle at the exit tube. Using the entry tubes one above the other as shown here allows 2 baffle tubes on the inlets, as in the photo above, which is a better breathing design.
The headers and fish tail silencer on the bike.
BSA V Twin
Photos copyright Zorsts.co.nz