Great post Dafydd, good info. Not really that silly a question though because even though we both know there is an engine test cell where the engine is setup for initial static testing, there is also an installed test that you have ably described. It is the final installation of the cooling configuration that I am highlighting and perhaps that configuration changed from the test configuration or perhaps it may need improvement if subsequent operating experience indicates the engines are running on peak or too close to peak temps. Of course what is defined as peak could also be pivotal in the survivability of the engine. I think if they can improve the cooling, many of the problems which are symptomatic of high temps will go away.
My mistake, I meant to actually say 'factory built models' which would include the certificated models and the LSA. By that comment I am suggesting that the factory built models should have properly functioning cooling installations and properly functioning CHT instrumentation which is fit for the purpose of operating the aircraft in accordance with the POH. Of course in the kit built versions, anything could happen and the factory would not be responsible. My understanding is that the factory built Jabs are also experiencing over heat symptoms.
Hell when they finally get this right, it will be a fabulous little engine and should do Jabiru and Australia proud. I personally want them to succeed and I really believe most of us feel the same. Hopefully many of the resolutions will be available soon.