Synthetic oil used in air cooled engines

by Alan
(Bronx,NY)

I have read that while synthetic oils are clearly better in maintaining viscosity and resisting molecular breakdown, a main job of the oil in an air cooled engine is to transfer heat away from the cylinders and head to the oil cooler and sump. Synthetics don't work as well with holding heat which as an advantage in a water cooled engine, can be a detriment in an air cooled one. This was my experience too in using synthetics in air cooled VW engines of which I still own two.