Oil Temperature Control

Its that time of the year to remove the oil cooler plate but that also means running with less than desirable oil temperature with this engine unless the OAT is 80. The engine runs cool.

So a 3" butter fly valve was purchased from ACS, a flange, a ratcheting cable and this is the end result.

It works mechanically, will see how oil temp is affected in flight very soon.

For those interested in controlling oil temperature and a method to do it, the flange is riveted to the winter plate which has a 3" cut out to pass air through the butter fly valve. The valve is riveted to the flange.

The bolt on the edge of the flange is one of 3 fasteners holding the plate to the aft side of the cooler, one on the visible side and 2 on the other side. The cooler attach bolts to the #4 baffle do not hold the plate to the cooler, those bolts are centered in holes in the plate so they did not have to be removed to remove the plate.

I had a similar device with the oil cooler remote mounted in the 7A. It worked very well. I learned a full open valve will cause #4 CHT to increase about 10°.

It not as complicated as it looks......and in this case the photo is not worth a few words.

Van's has a device to control air through the cooler, it works also. It needs a cable from the side to move it, this valve is opened and closed with a cable coming straight back from the cabin.

David,
These butterfly valves typically provide a temperature variation between full open and full closed, I've had good success with them. However, by blocking off the cooler in front of the valve you are restricting the 'normal' airflow through the cooler substantially. I'd suggest fabricating a funnel of sort so that the cooler benefits from air passing through all of the fin area and not channeling through the center. You will almost certainly see hotter than normal temperatures with the valve wide open than before the valve was installed with that 'blocker plate'.
Also, the 2 point mount for the cable stand off may or may not stay put. I like to use a 1 point or a 3 point to keep the cable stationary. What happens is 'someone' will pull on the cable with enough force to reposition the stand off resulting in a less than desirable position.
Let us know how it works out for you, I for one will be interested in your results.

Good point Rick. I thought about having that much of the fin area blocked and wondered how it would affect cooling, as you say, it will be less than optimal. A funnel would be better.

But this engine runs so cool, I seldom saw 170 last summer with the cooler wide open. A few flights in hot weather will tell the story. In this case less cooling efficeincy is needed, not more.

One reason cooling is working with this engine may be because I opened the cowl exit area forward about 4". With 4 pipes in the exit area, I figured a little more exit area was called for.