RE: How does a gas engine act when hot?
The thing about gassers is that they will continue to run when overheating. The biggest tell tale sign would be sagging at high throttle settings. Truth is that you can run at close to 300 degrees and really not know it. You can always read the plug color but usually if you have run it hot long enough to do that it may already have some damage. Having muffler bolts constantly coming loose is a sign of overheating. If your worried about the install make sure you are directing air through the fins. Its always easier to pull air rather then push it so your exit area need to be at least twice the intake area. Don't wait until you have an issue, plan ahead so you don't have an issue. I'm currently rebuilding a 40% Extra that is a good example. notice I have 2 exits, one at the bottom of the cowl and one just behind the canisters.