Morning chaps,

What thickness of pipe is best to use for a bike carb manifold? Will exhaust pipe thickness do or thicker? Pipes will be about 2 inch long.

Thicker stuff will be easier to weld.

Stu

Ideally, the ID will match the port diameter and the OD will match the rubbers that hold the carbs.

Mine was 42mm x 2mm.

I made my one for my zetec using alloy scaffold tube, its 50 OD by 40 Id and squashes to just the right size for the port.I had to turn a section down for the connecting pipes to fit.
I also made a steel manifold for my crossflow and that was made from 38mm exhaust tube and 10mm steel plate. I have seen a number of manifolds made from stainless tube about 1.5mm with a 5 or 6mm flange so lots of options depending on how you intend welding it.
Paul.