>>As a general request, I would like to solict opinions on what folks
>>would consider a max oil temperature in an air cooled engine

John:

I have the sender installed in my '81 Vanagon, but not (yet) the
gauge, so I can't offer any comparison temps.

However, in the Porsche Panorama there are frequent questions about
old temps over the years.  The tech chairman, Bruce Anderson, likes
to say that 220-230 is HOT and 250 is TOO HOT.  However, he has
also noted that in high, dry climates (like Colorado), one can
expect 250 in the summer.  My old '72 911T used to hit that; my
'88 Carrera runs a little cooler in the summer.  These engines
have 11+ qts of oil and an oil cooler mounted in the right front
fender....

Anderson says that around 250 is when the oil starts to break down.

                                Richard A. Jones
                                Boulder, Colorado
                                '81 Vanagon  Mr Bus