I understand that many VW motors, some WBX included, have the oil
filter/coolant heat exchanger like the one 'above' the oil filter that I
found on my 93 Jetta (recent) transplant block. I just swapped this new ABA
motor into my 84 vanagon  in place of a 92 1.8liter  inline VW.  The
1.8l motor has no exchanger like that.  Looking at this thing, it seems a
bit....useless?

  Is it supposed to 'cool' the oil?  Heat the oil? Up or Down to the temp of
the coolant?   That temp. is about 188f with an 87c
thermostat...about normal oil temp anyhow.  The temperature difference, as
influenced by the coolant circulating around the oil filter pipe, is that
same condition not present all over the motor?  As coolant circulates
through the head and block, it shares the same contact with the metal as the
oi/ in adjacent passeges, right?  Is there a real advantage to adding that
extra small 'interface' at that "cooler? Heater?" ...whatever you would call
it?   It looks like there might be very little thermal exchanging going on
there, between the oil and the coolant, given the surface areas involved.

 It seems like that device just a couple of extra hoses and clamps to an
already painfully complex cooling system,  for not much 'real world'
difference, other than another possible failure point to lose coolant..
Looks a litte cheesy, too..that stamped chamber of flimsey alloy.

  My 1.8 liter without that type exchanger had no issues whatsoever
involving oil temps in the 60k hard hard miles I put onto it..

  Just curious..any body else have an opinion or give a darn about this
little widget?

  PS...I am leaving mine on there, for now, without any coolant circulating
through.  I might sometime hook it up and monitor the oil temp...see what
happens in the motor...I bet Not Much..

  Don Hanson