[Tigers] oil temperature

[Owain Lloyd]

i just installed an oil temperature gauge and found that after a hard run
the water temperature is about 180F (the thermostat temp - i need to change
that up to a 190), but the oil temperature reaches about 260!

what is the normal acceptable temperature for engine oil?  i'm trying to
decide whether or not to fit an oil cooler.  i'd be happier if the temp was
under 210 but thats not based on any particular knowledge!   i'm using mobil
semi synthetic if that affects the acceptable extremes.

on a side note, i recently changed to lighter oil (mobil 5W30 instead on
10w40) after finding hot cranking difficult to impossible. this fixed the
hot cranking issue, but i guess i could switch back to 10w40 if the oil was
running cooler?

thanks again for wisdom of the list!