  We have measured the redshifts and single-aperture velocity dispersions of
eight lens galaxies using the data collected by the Echellette Spectrograph and
Imager (ESI) and Low Resolution Imaging Spectrometer (LRIS) at W.M. Keck
observatory on different observing nights spread over three years (2018-2020).
These results, combined with other ancillary data, such as high-resolution
images of the lens systems, and time delays, are necessary to increase the
sample size of the quasar-galaxy lens systems for which the Hubble constant can
be measured, using the time-delay strong lensing method, hence increasing the
precision of its inference. Typically, the 2D spectra of the quasar-galaxy lens
systems get spatially blended due to seeing by ground-based observations. As a
result, the extracted lensing galaxy (deflector) spectra become significantly
contaminated by quasar light, which affects the ability to extract meaningful
information about the deflector. To account for spatial blending and extract
less contaminated and higher signal-to-noise ratio (S/N) 1D spectra of the
deflectors, a forward modeling method has been implemented. From the extracted
spectra, we have measured redshifts using prominent absorption lines and single
aperture velocity dispersions using the penalized pixel fitting code pPXF. In
this paper, we report the redshifts and single aperture velocity dispersions of
eight lens galaxies - J0147+4630, B0445+123, B0631+519, J0659+1629, J0818-2613,
J0924+0219, J1433+6007, and J1817+2729. Among these systems, six do not have
previously measured velocity dispersions; for the other two, our measurements
are consistent with previously reported values. Additionally, we have measured
the previously unknown redshifts of the deflectors in J0818-2613 and J1817+2729
to be $0.866 \pm 0.002$ and $0.408 \pm 0.002$, respectively.
