Drain valves versus plugs versus suction

[Phil Payne]

> You forgot to mention the acidification of the oil due to the combustion
> products of water, H2SO4 and CO2 in the crankcase. IF the oil doesn't
> regularly get warm enough to boil off the water, it combines with the
> other combustion gases to produce various acids. The acids will only form
> in the presence of water (acid is simply a dis-sociation of water, as are
> bases), so if there is water in the crankcase (also a byproduct of
> combustion), from frequent short trips, then you would need to change the
> oil to fight acid build up.

There is a known phenomenon on early WR engines where the bores suffer
significant botton end damage if the car is left for periods of months
between runs.  Only seems to affect cars up to about 1983.  I think this is
a likely cause of the problem.

--
  Phil Payne
  http://www.isham-research.com
  +44 7785 302 803
  +49 173 6242039