
Many, many moons ago, I owned a 1946 Cessna 140. Cessna specified 40wt oil for it. It had a 90HP Continental 4 cyl air cooled engine.
I'd think that 40wt would not be out of line for our older air cooled engines. I'd certainly go no lower than 30wt.
Posted August 12, 2011 - 08:32 PM
Posted August 13, 2011 - 08:15 PM