  We present time-resolved spectroscopy and photometry of the double-lined
eclipsing cataclysmic variable V347 Pup (= LB 1800). There is evidence of
irradiation on the inner hemisphere of the secondary star, which we correct for
using a model to give a secondary star radial velocity of K_R = 198 \pm 5 km/s.
The rotational velocity of the secondary star in V347 Pup is found to be v sin
i = 131 \pm 5 km/s and the system inclination is i = 84.0 \pm 2.3 degrees. From
these parameters we obtain masses of M_1 = 0.63 \pm 0.04 M_\odot for the white
dwarf primary and M_2 = 0.52 \pm 0.06 M_\odot for the M0.5V secondary star,
giving a mass ratio of q = 0.83 \pm 0.05. On the basis of the component masses,
and the spectral type and radius of the secondary star in V347 Pup, we find
tentative evidence for an evolved companion. V347 Pup shows many of the
characteristics of the SW Sex stars, exhibiting single-peaked emission lines,
high-velocity S-wave components and phase-offsets in the radial velocity curve.
We find spiral arms in the accretion disc of V347 Pup and measure the disc
radius to be close to the maximum allowed in a pressureless disc.
