Having seen some Gene Berg custom carbs I was idly wondering if you could use a 3D printer to draw and print/extrude/form a carb or a throttle body with only a little metal assembly like butterfly/throttle linkage.

Using a nylon printer as ABS does not look too good for petroleum at 75-105 degrees under bonnet conditions?

(judging by http://www.lati.com/en/technical_data/chemical_resistance_01.html chart for lastilac ABS).

It's clearly possible to draw one in 3d

http://grabcad.com/library/carburetor-2-barrel-volkswagen

Might work but imagine it would wear out much quicker than a metal one, a carb anyway.