LSR how to move clefs on uneven staff lines?

[Till Rettig]

Hi, I tried to get the clef right for this example from lsr:

upper = \relative c'' {
 c1 d e f
}

lower = \relative c {
 c1 b a g
}

\score {
 \context PianoStaff <<
   \new Staff <<
     \upper
   >> 
   \new Staff  {
   \override Staff.StaffSymbol  #'line-count = #4
   \set Staff.clefGlyph = #"clefs.F"
   \set Staff.middleCPosition = #6
 \set Staff.clefPosition = #2
 \set Staff.clefOctavation = #0

      %\clef bass
       \lower
   }
 >>

}


But it doesn't change the position of the notes or the clefs. What is 
here wrong? I tried as in NR 1.1.3.1

Greetings
Till