While living in Alaska for many years, I found circulating engine
heaters and freeze-plug block heaters to be a necessity of life. The
circulating heaters were typically 1200/1500 Watts and were usually
installed in the cooling system plumbing and worked on a thermo-siphon
principle. The heated water circulated through the engine block and the
energy flow was sufficient to loosen the oil for starting.  The
freeze-plug block heaters were 750W and worked similarly, but a
freeze-plug in the block was removed for its installation. Again, it
worked by heating the water in the engine which in turn heated the block
and the oil.

I lived in Fairbanks for a time and found the circulating type  heater
to be a salvation. Back then, the block heaters were pretty weak by
comparison. When the temperatures get to -45F or colder, the oil in the
engine is like glue and the 1500W circulating heaters were a necessity.
In those days I drove a Volvo and a jeep.

Later, in Anchorage and down on the Kenai Peninsula I drove a Loaf for
years. I had a VW oil-sump heater installed externally on the oil screen
ring on the bottom of the engine. Surprisingly, the thing worked
extremely well, even at -35F. Always started....if I remembered to plug
the heater in at night. If not, it behaved as if the engine was seized.

I later bought my first vanagon, a 1985 GL. I installed a supposedly
"official" VW crankcase heater that was made to fit onto the bottom of
the wasserboxer engine, but didn't really because of the way the engine
block is cast. That heater was about as worthless as teats on a boar.
There was to much gap-osis between the metal of the block and the
heating ring of the heater. I never did find an adequate coolant/block
heater for that vehicle. Haven't found one for the current vehicle
either, and "88 GL.

I feel that the best preheating system for the watercooled Vans would be
some type of circulating heater installed in the cooling system
plumbing. The heated water would do the best all around job of
adequately heating up the engine and oil before starting in really cold
weather.

I know that outside of Alaska, other parts of the continent north of the
Mason/Dixon line have really cold weather, so other van owners in Canada
and the states have had to deal with this issue. Would love to hear of
specific esperiences and the specific solutions.

John Rodgers
"88 GL Driver currently in New Mexico