the numbers from Continental include a very wide range in the "normal" category.  I've got about 70 hours on my engine.  It was fine during the test flight hours, about 185 oil temp, but shot up after that.  If oil temps redline at 240, I don't necessarily want to cruise all day at 235.  Same with the CHT's, that's the reason for the question.  If I put in larger exit tunnels, I can bring down the CHT's but do I need to?  If I want to "fine tune" my temps, what should be my target. 

 

Mike,

 

Newish experimental airplanes have some of the weirdest problems.  Sometimes construction junk get to places it shouldn't.  When did you last change the oil filter?  Has the oil pressure indications changed from before (when there were more normal temps)?  Are you using a different grade/wt of oil?  Is there a rag stuck inside the engine and blocking the oil cooler line?  Has some debris collected in the oil cooler internally (flush it?) or in the cooler air passages?  What else in the engine compartment has changed just before the hi temps appeared? Any electrical changes that might affect the temp probe or its wiring? It is very unusual for temps to rise after "breakin".  It is not simply high oil temps, but strange symptoms with new ones being slowly revealed.

 

If the CHTs have gone up, have you checked the mag (if any) for timing? - if it drifted towards advancement, temps could go up.

 

Have any baffling changes occurred?  Where is the oil cooler located and can air be drawn away from it now (You have been using the heater in this colder weather and it takes air away)? 

 

Don't rush into cowling modifications - there are many experiments that can be made before modifications are made.