  We simulate Quantum Chromodynamics in four Euclidean dimensions with two
(degenerate mass) flavors of dynamical quarks. The Dirac operator is the
so-called chirally improved operator that has been studied so far in quenched
calculations. We now present results of an implementation with the Hybrid Monte
Carlo (HMC) algorithm including stout smearing. Our results are from an 8^3x16
lattice with tadpole improved Luescher-Weisz gauge action. We present our
estimate of the lattice spacing, the pi and rho meson masses and evidence for
tunneling between different topological sectors.
