So L.S.Griffiths@physics.salford.ac.uk says:
>      a heater box exhaust tube - without the heater box shroud and fins.
>      I am going to weld a water tight tube around this J-tube as below:
>      
>      J tube \ ___
>              /               water tight tube
>        out__|_____________ /
>              \_|__________|___
>                |__________|_ 
>                              in
>      
>      Then (change of tense) add an inlet tube at the bottom towards the
>      rear of tube and an outlet tube at the top towards the front of the
>      tube. We thought that the cold water should enter the water box as 
>      far away from the exhaust port (of #3) as possible to minimise exhaust
>      tube cooling. Cooling the exhaust might result in large exhaust 
>      pressure difference for number 3 cylinder - something to think about.
>      
>      Ok so then fit a water pump (electric or fan belt driven) obtained 
>      from a junk yard to power the water around. Then two 15mm copper house 
>      radiator pipe the water to and from the cab. In the cab fit an 
>      all-in-one radiator and fan unit from a, you guess it, small Italian
>      car. Seriously all small water cooled FIATS seem to have these nice
>      little water heater units in the engine bay that consist of a small
>      radiator and boost fan in a nice little box. Connect the copper
>      pipes to the in and out tubes on the FIAT radiator and mount it
>      somewhere under the dash board and err, maybe bingo you have a toastie
>      bus in winter. Well I'll let you know if it works.
>      
>      Some other points to note are that you will need a header tank in the 
>      engine bay to "let off steam" and don't forget that foam lagging round 
>      the copper pipes. Don't worry about boiling in Summer, just drain the
>      water off coz you'll not need the heater in summer.
>      

I realize this is my third response to this thread, but fingers just love to
hit that send key. ;)  Anyway, I just realized that this system might be a 
solution for those with air-cooled Type II's that want to have heated water/
showers in their beasts similar to Dave Garths magnificant system.  I think
alot of people will be interested in your results Lee.

Good Luck!

Steven

sjohnson@pcocd2.intel.com