Today, while in my car, I noticed
that the normal oil temp range is 200 to 250, the gauge goes as high as
300 - my engine was running with an oil temp of about 225. (I use a
multigrade synthetic oil in my car.) This made me wonder why the normal
oil temp range in airplane engines top limit is 240.
- Is this top limit of 240 based on engine issues
or on oil issues?
- If the cylinder head temperatures are normal,
does having an oil temp above 240 hurt the engine?
- Does having an oil temp above 240 cause the oil
to break down or lose some of its properties?
- Was this limit set at a time when oils
were formulated differently than today?
- What harm is there in exceeding an oil temp of
240 for a short period of time?
- What about a long period of time?
I am not planning to set up my engine and
baffling so that I routinely exceed 240, but have had the experience in my
current plane (Mooney Ovation) of exceeding 240 while idling on the ground in
hot weather. Just wondered how much of a problem this really
is