  We investigate the influence of dry friction on an asymmetric, granular
piston of mass $M$ composed of two materials undergoing inelastic collisions
with bath particles of mass $m$. Numerical simulations of the Boltzmann-Lorentz
equation reveal the existence of two scaling regimes depending on the strength
of friction. In the large friction limit, we introduce an exact model giving
the asymptotic behavior of the Boltzmann-Lorentz equation. For small friction
and for large mass ratio $M/m$, we derive a Fokker-Planck equation for which
the exact solution is also obtained. Static friction attenuates the motor
effect and results in a discontinuous velocity distribution.
