SkyPilot, take a look at post 4 and 5 above. They are VERY GOOD information as to my own personal experience with temps. I use a themocouple type meter made by Fluke on the bench and a Venom temp recorder on the plane or in some cases my Eagle Tree flight data recorder. My observations match Bill's, Andrew's, Dave G.'s, and Clarence Lee's very closely. I am one of those nuts that can never have "too much" data to crunch to try and improve performance. (Dang speed freaks why can't they just fly slow like the rest of the folks) LOL, have a good one.

Sorry, I forgot to add that my gassers tend to run just a touch hotter, about 15 or 20 degrees, but that is not hard and fast. Some of my gassers stay under 300 to 310 and a couple are up around 330 or 340. It does vary some based on ambient temps outside and I use it as a baseline to see where I am at relative to the last time I checked a particular setup. It's just another tool in the arsenal of trying to get that last nth degree of power out of her.

Also, some temps I've looked at on my engines

OS 40FSR = 330 to 340
SuperTigre G40 = 290 to 300
SuperTigre G51 on Gas = 300 to 320
Saito 91 on Gas = 320 to 330