The shop manual says SAE 20 for most climates and SAE30 for hot climates. I wouldn't go much thicker than that or your rods may not get lubricated well. It's easier to kill a 216 with oil that is too thick than oil that is too thin.
Castrol sells a SAE 5W20 oil that Honda specifies for their new cars, which is perfect for winter use in a 216.
