I have a temp probe at the outlet of my carb. In a recent test at 3000', 4350' dalt, 203 mph, 21C OAT, I was seeing 18C-19C carb temp. The stagnation temperature rise into the carb inlet should have been about 4C, giving an inlet temp of 25C, so the drop was 7C-8C. This is a little more than I would have expected for two reasons; CF Taylor says that the typical temperature drop due to fuel evaporation should be about 24F, 13C, and my carb is on a fiberglass extension on the back of my carbon-fiber pan and should see less conductive heating than the typical Lycoming set-up on the bottom of the pan. 'Can't explain the 5C-6C difference!
