High oil temp.. again...

My oil temp runs around 220 in the summer. I am told this is running on the upper edge of acceptable temps. What should I do to improve this? My cowling seals appear great (they are almost brand new). A A&P said I should move the oil cooler up a little, more in line with the air flow over the rear cylinder. How much is a little? I am going to install a spinner soon, this may help a little. Anybody have any ideas?
This is on a Smith Kit Cub, so I can really do whatever I want.

Mike

Have you read the various threads on this? "in the summer" can mean a lot of things...for example, today, I was running 225 F on my oil temp. With 80F outside air temp...36% humidity, 7.5 gal/hr, 5500 ft., 2500 RPM on a Borer 44" prop, 80mph indicated, 1460 F EGT... Could you be a bit more specific? This was after 45 minutes of letting it heat-soak, too. I started out at 210 F at about 15 minutes....if you have a cooler on your rear baffles, you got problems, buddy. By all means , move it up as high as it will go, then connect another one in series, mounted on the front ramps...
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Assume from the get-go I don't know what I'm talking about, and you'll be safe... :roll:

More specific?

More specifics? Every time I fly, in just a few minutes my oil temp is showing around 220 degrees. I usually fly around 2500'. The high oil temp doesn't seem to be a function of throttle or OAT in the summer. It runs just as hot at 2200rpm as it does at 2500rpm. Its on 220 degrees at 80 degrees all the way to 97 degrees. And yes, the oil cooler is at the rear baffle of the left bank (sitting in the airplane).

Mike

We got better differential pressure between the upper deck and lower deck by moving the cooler back away from the cylinder. Dropped 10 or more degrees. Also sealed up around the air box to keep that air from disturbing the exit air. Everything I have flown has an oil temp which was relative to OAT in level fight.

Do you have a vernitherm installed? Sounds like that's where it's set to release oil to the cooler....
I don't worry too much about 220....that's where oil is designed to be run, one degree higher, and I stert worrying...

Gauge calbrated?

Hi,
New here and not sure what engine you are running. Cont. has a vertatherm in the larger engines that is a oil temp thermostat. It simply when hot reroutes the oil through the oil cooler not around it. It is adjustable. I will tell you from personal experience that even a factory reman can have a vertatherm way out of adjustment.

Tom
Cape Cod

In your spare time I would try this order ,

fill every hole in your baffles that is not supposed to be a hole with some silicone. your choice of color.
even small holes leak pressure without transferring heat.
usually good for dropping 5 - 10 degrees

Make sure the baffle seals point the right way.

check inter-cylinder baffles, are they correctly installed? I like to add rubber strips to the edges where they ride on the cylinders, so they don't chafe holes into themselves.

make sure the cooler fins are clean. NO paint or dirt.

Check the seat for the vernatherm. and on the vernatherm. should be concentric and even.

Check for obstructions in the lines. sometimes hose linings do fail.

High Temp..

Mark,
There 'aint no holes in my baffles. This plane has 70 hours total time on it, and its darn near spanking new. It has always run about 220 on oil temp. The rubber seals inside the cowling are perfect, it just runs on the ragged edge of being to hot. The engine is a XP-360 from Superior, and uses no oil. It has 9:1 compression, but I doubt this has any bearing on the oil temp. It does have a vernatherm, and I'm going to pull it out soon and see if the oil temp runs cooler. If that fails, then I'm moving the oil cooler back from the rear cylinder baffle.
Thanks for your input.

Mike

Mike,

I know you probably already know but: If I am not mistaken pulling the vertatherm out and plugging the hole will not work. The vertatherm heats up and closes off a port and forces oil through the oil cooler...so pulling it will only allows the oil to bypass the cooler.

Tom
Cape Cod

You would need the ball and spring if you pull the vernitherm out. I would suspect oil temp gauge. I have flown to mny airplanes with oil temps all over the place. The Pacer today at over 100 dgrees never got over 200. It was at 120 this morning before I flew it. Several similar experiences with other A/C.

Like Steve says, ya don't know squat until you know that your gages are calibrated!!! :roll: :roll: :roll:
ps...remember that water boils at different temperatures depending on the altitude of your shop!! :roll: :roll: :roll: