Remote oil thermostat

[Kurt.A]

One last point I'm going to make here.

I have a 912 UL (80 hp) in my yellow plane. I have NO oil cooler on it. Zip, zero, nada. On the hottest of summer days, after long sustained full power climb, my oil temp may get to 250 degrees Fahrenheit. Yes I live in Wisconsin, not Arizona or Nevada. But it does get into the high humidity, 90s here during the summer.

I use Mobil 1, Racing 4T oil. With this oil my temp redline from Rotax is 280 degrees Fahrenheit. I've been told by LEAF, that this oil remains stable and will not coke well above 320. I don't need an oil cooler. I don't want the complexity of tubing and weight of an oil cooler on this already nose heavy plane.

With modern oil technology, high temps usually aren't the problem. I've seen more problems with prolonged low oil temps.

Just something to think about.

Now that is an excellent point! I was not aware that I could effectively remove the cooler from the circuit without causing oil degradation. I agree 100 percent that oil temps of your experienced 250F are perfectly fine with the use of high quality synthetic oils. Plus you get the advantage of less forward weight, less complexity, and less failure points. Every ounce of weight saved is a benefit in my opinion. Thanks for posting and I am glad we had this discussion.

[AirFox]

Can someone give me an example of "prolonged low oil temps"?

[Av8r3400]

Prolonged operation with the oil temp never exceeding 150 degrees Fahrenheit.

This causes a buildup of dissolved water in the oil, hampering the lubricity and potentially causing corrosion internal to the engine and gearbox. This is especially important if you are running 100LL.

When running 100 LL it is imparative that oil and cylinder head temps exceed 200 degrees to keep lead buildup from happening.

[AirFox]

Prolonged operation with the oil temp never exceeding 150 degrees Fahrenheit.

This causes a buildup of dissolved water in the oil, hampering the lubricity and potentially causing corrosion internal to the engine and gearbox. This is especially important if you are running 100LL.

When running 100 LL it is imparative that oil and cylinder head temps exceed 200 degrees to keep lead buildup from happening.

Thanks for the advice. I have a uls with the newer cylinders. I have the oil cooler and thermostat. My oil temp never gets over 200. Usually runs around 160. The last month I covered the oil cooler and still didn't get the temps over 200. Good real world info in this thread.

[Av8r3400]

I don't have one, so someone please correct me if I'm wrong, but I thought that the oil thermostats under discussion in this thread are designed to open at around 180º F.

This would also jibe with what we were told in 912 training that the water doesn't really start evaporating off from the oil until that 180º level has been reached.

[jiott]

I have the oil cooler mounted on front of the coolant radiator and have the thermostat (I believe it is 180 degree but not 100% sure). When the weather turned cold last month I was not seeing oil temp much over 160. Then I taped over the oil cooler with a 2" wide strip of aluminum tape (which also blocks air flow thru that part of the coolant radiator) and now see my oil temps up at 210-220.

Also remember that the oil temp sensor is at the oil pump, which is probably the coolest point in the oil circuit. I wouldn't be surprised if the oil temp in the engine galleries was over 250 degrees.

[Kurt.A]

Can someone give me an example of "prolonged low oil temps"?

Prolonged low temperature oil does not allow water to evaporate off as posted. The scary part of all this is the chemical reaction that takes place in the oil. In severe conditions the oil turns turns acidic and starts to eat away at the metallic components within the eng. This is one of the reasons to use a very high grade synthetic oil. The modern synthetics contain considerably more additives that combat these types of issues. Best defense is to maintain normal operating temperatures, use high quality synthetic oils and perform your oil changes religiously.

[Meyertheflyer]

I have an oil thermostat that I'd like to install. Does anyone have a picture of their installation on a model 7 super sport that they could share. If not, I'll post one when I'm finished. Thanks

[Paul Z]

I just installed mine. I looked at a new SLSA at the Factory, it was a lot easier than I thought. I'm going to the airport to finish my annual. I'll take some photos, since my cowling is off I can get them pretty easily.

[Meyertheflyer]

Thanks Paul, I appreciated it.