Yesterday, we flew 6 hours doing some training, so enroute, had time to do some experimenting. I was surprised to find our actual CHT's were lower 50 LOP, than they were 50 ROP.  As expected, fuel flow dropped from 20 gph ROP to about 16.1 LOP and we lost some airspeed. We had a slow build kit, and it took us six years, so due to construction time, we don't have any warranty left from Continental (that little gotcha - just another reason fast build is the only way to go today) so want to do what is best for this longest possible life of the engine.  We have been running 50 Rich.  I am getting the impression that in fact, there is a time to run ROP and a time to run LOP, based on other factors.  Any thoughts?

 

As I am based in Western Canada, attending the course recently praised in this forum is not a simple option, but I sure would like to know what the proven facts are about this issue.