Cessna 172 Oil Temp

According to the type certificate data sheet for the O-300D the max
allowable inlet temperature for the oil is 225F. I've always done an
"eyeball" test with a hot plate and boiling water. If the needle is about a
needleandahalf below redline, that is about right.

I looked at the tc for the Cessna and strangely enough, it doesn't specify
the redline temperature. My 172 manual got burned in a hangar fire about
ten years ago and I haven't gotten around to replacing it.

Jim



The 172 users manual says temp should be in the green with max allowable
temp at the red-line. Anyone know what the actual temp is for this 172 at
red-line, any way to calibrate the gauge?

Thanks for your help
Gary