If I set beamExceptions to beam 32nd notes by fours in 4/4 time, this
has the side effect of changing the beaming of 8th notes:

%=====================
\version "2.15.40"

changeBeaming = \set beamExceptions =
     #'((end . (((1 . 32) . (4 4 4 4 4 4 4 4)))))

\relative c'' {
     c8 c c c c c c c
     \repeat unfold 32 { c32 }
}
\relative c'' {
     \changeBeaming
     c8 c c c c c c c
     \repeat unfold 32 { c32 }
}
%=====================