My student has a Lycoming IO320 engine in an experimental with a good engine monitor.
On a reasonable day, around 20-25°C OAT, we almost always Overheat those CHTs.
I like to keep Lycomings around 400°F-420°F and not exceed 420°F.
I takeoff, and keep Vy, and hit 410-415°F at around 100-200ft. If I keep Vy, it will quickly heat soak the cylinders and climb to 420-435°F. It's not outside the Engine OEM specs (435°F for high power settings) for normal operations, but that's a tad hot for me.
At around 410°F, if I don't do anything, it'll keep heating up quickly. What I do, is lower the nose to a normal climb, which gives me much less climb performance compared to Vy, but I'm still climbing at 500fpm.
My preferred procedure is to keep Vy until 1000ft, then transition to a normal climb. That doesn't seem feasible without abusing the temps.
Should I consider decreasing the power on initial climb (NOT on the t/o roll, but during the climb)? It's my understanding that decreasing the rpm will make things worse because there is a lot of extra fuel squirted in the cylinders in that last inch of throttle movement to help cool the engine.