In article , G.R. Patterson III
wrote:

212F sounds a bit low. While that is the boiling point of water,
most of the Lycs I've flown behind have a max oil temp of around 240F.

Ben Vissar of Shell Oil gave a presentation to our aerobatic club many
year ago (10). He stated that there is a 50 degree F temperature
difference between the temperature probe in the sump and the oil
bathing the hottest area of the piston/cylinder.