I'm going to play devils advocate here a little bit, not arguing but posing legitimate questions that come to mind about this. In my predator, I run 13oz. of Mobil 1 5w-20. I change it every race. This is may not be the "best" but it works for me and I have yet to have any issues with it. When I checked it over this off-season it was clean as could be. I am very, very particular about maintenance, cleaning, etc.
I get drawn.
I then give my motor, that is in basically perfect condition, properly tuned, well maintained, etc. to another competitor. He/she then gives me their motor, which may or may not have been being maintained like mine. It may or may not be tuned properly, may not have had the regular oil changes, health checks, etc.
Am I supposed to just be happy with this? I'm not even talking about what may or may not have been done to their engine machining wise. I'm just talking about simple things like maintenance. Personally, I check every oil change for metal, I bore scope the cylinder from time to time, and at the end of the year I open the case to look everything over. I am within the rules, whatever they may be, and now I am getting handed an engine that I have no idea the history of? I am just supposed to accept that the engine I am receiving is as good as the one I am giving?