Many years ago I bought a ThermaCowl to operate the cowl flaps on my Corsair according to the temperature in the engine bay. It has worked perfectly for many years but I can't locate the original supplier in the states. Does anyone know of a similar product?
Only just seen this, but what radio system do you use? several have telemetry temperature sensor feedback which can be used to operate a channel, so you could have automatic operation using a servo via a spare channel on your transmitter.