  We study semi-analytically and in a consistent manner, the generation of a
mean velocity field $\bar{\mathbf{U}}$ by helical MHD turbulence, and the
effect that this field can have on a Mean Field Dynamo. Assuming a prescribed,
maximally helical small scale velocity field, we show that large scale flows
can be generated in MHD turbulent flows, via small scale Lorentz force. These
flows back-react on the mean electromotive force of a Mean Field Dynamo through
new terms, leaving the original $\alpha $ and $\beta $ terms explicitly
unmodified. Cross-helicity plays the key role in interconnecting all the
effects. In the minimal $\tau$ closure that we chose to work with, the effects
are stronger for large relaxation times.
