Type 2s never used the frame rails (like the Type 1/3/4) for heat transfer
(or appropriately "attempted heat transfer") from the rear to front.  On
Splitties and some Bays it is via a large insulated metal tube, later Bays
used the same/similar ducting the Air Cooled Vanagons utilized, all in the
center of the vehicle.  Stationary heaters usually had their own ductwork
from the heat to the rear passenger compartment on Splitties and Bays thru
1971.  In 1972, the BA4/6 was designed to work with the center tube to
provide heat in a better fashion to the front
-- 
Jim Thompson
84 Westfalia 2.1 "Ole Putt"
73 K Ghia Coupe "Denise"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
**********************************
On 9/22/06, Mike Rouby <mikerouby@yahoo.com> wrote:
>
> It is true, but not for post-1990 South African "Vanagons", as they use a
> different gas tank (don't Syncros do as well??)
>
> The older T2 vans used the framerails I believe, a la Bug, to dispense the
> heat to the front aka heater channels.
>
>
> Todd Last <rubatoguy@COMCAST.NET> wrote:
> GoWesty writes....
>
> " Interestingly, the depression down the middle was put there to allow the
> hot air duct to pass from rear to front on air cooled Vanagons. Even though
> there is no purpose for it now, and even though 90% of all Vanagons ever
> produced were water-cooled, the fuel tank design never changed. Go figure�."
>
> Is this true?
>
> I thought all the cooling air came through the side vents at the rear of
> the van...
> and if this is necessary... why did none of the type II vans have it??
> Seems a rather suspect explanation to me... If anything, I thought it
> would be there to help the air exit after the radiator for the water cooled
> models.
>
> Todd
> '88 Westy