Posted for "Marc Wiese" <cardmarc@midsouth.rr.com>:

Al

Unfortunately the 20B used a cast iron water pump (like the 13B to 1991
but maybe run in reverse, I haven't confirmed that). The 13Brew
(93+)has an aluminum pump AND housing.

The 13B rew has a water pump that is different than the 13s before it.
The pump and the housing it is mounted in is aluminum.  The radiator
heat dissipation capacity was increased (to 40,000 kcal/h), and the
radiator cap opening pressure was increased (to 16-21 psi, but a recall
adjusted that again). No figures on flow rates were given. [Marc Wiese]