I thougth of that also, but wouldn't I see some rise in the oil
temperature if I restrict the airflow through the oil cooler by 2/3s?
Speaking of Arrow's, I talk to an owner that was putting on a
winterization plate on his oil cooler, and I think it was a plate with a
1.5 D hole in it. That seems like a lot of restriction.

Ross

Aaron Coolidge wrote:

Ross and Paula Richardson wrote:
: I own a '65 Cessna Skyhawk with a Lycoming O-360-A1A turning a constant
: speed prop. I recently read an article in the Cessna Pilot's Association
: on too high of oil temperatures, but that is not my case. I have been in
snip

A friend's Arrow (IO-360-C1B?) had exactly the same symptom. The oil temp
runs at about 130F no matter what. The Lyc engines have a "vernatherm" to
bypass the oil cooler below some oil temp, and his was hung up wide open.
It's on the co-pilot's side of the oil filter adapter under a big nut with a
copper crush washer. You can heat it in an oil bath to see if it changes,
and check the bore that it rides in for a worn spot that it may catch in.
You can also touch the oil cooler & hoses to see if they're hot/warm/cool.
You could also pull out the dipstick & measure the temperature with your
DMM attachment.
If the oil cooler is pretty warm I'd really suspect the vernatherm valve.
It should be quite cold if the oil is less than 180-ish degrees.
--
Aaron C. (N9376J)