You can get block heaters for the air-cooled engines though I doubt they are
still made.  A company called Kat made them for a long time.  In the
nineties I picked up the Kat heater for the older upright fan engines and
one for the pancake engines from a friend that worked at Kat.  They are
simple devices and you could make one by using the heating component from an
electric gill or similar.  These heaters bolt on below the oil strainer and
when plugged in they heat the oil/case from this external location.

The heater makes it possible for me to not only have a decently running
engine on really cold mornings but to be able to shift gears without waiting
15 minutes.  Fortunately it has been years since I plugged my engine heater
in.

Jonathan Poole
'83 AC Westy

Date:    Wed, 11 Mar 2009 23:25:32 -0500
> From:    Jeff Palmer <jpalmer@MTS.NET>
> Subject: Re: Takes a darn long time for the heater to come up to speed
>
> My understanding was a block heater heats the coolant via the block.
> Can you have a block heater on an aircooled?
>
> Jeff
>
>