Oil thermostat vs adjustable oil cooler blocking

[JoeRuscito]

We’ve had some really cold temps (for CHARLESTON) lately, 24-30 Degrees F at altitude. I have quite a bit of my oil cooler blocked off and rather than keep chasing the temps with aluminum tape I’m considering other solutions. At cruise I’m seeing 170-185 degrees for the oil temp and sometimes as low as 130s for coolant temps. A note that is with my cabin heater at full blast. I want to hear everyone’s experience with adding an oil cooler. Also how does this compare to adding adjustable louvers that block the oil cooler? Are both needed?

is a coolant thermostat ever used?

[Dorsal]

I use a thermostat on both oil and coolant, Engine warms up pretty quickly and temps remain quite stable. Have no experience with louvers so can't comment on that.
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[JoeRuscito]

What thermostats do you use and what temp do they hold the fluids at?

[Lawdog]

Timely topic: I have been considering a similar solution to cold weather flying and engine temps. I fly year-round in the Colorado high country and use the blockage method. Air temps are often in the single digits in the valley and inverted at altitude, or vise versa. Makes it very difficult to maintain consistent, and proper, oil temps and CHTs.

Very curious what type of thermostats are working for both oil and coolant. Thanks in advance for any details willing to share.

[Dusty]

A note of caution, the 912 is a full flow system and most water coolant thermostats stop this flow. A bypass type allows flow at all times. I have is used a bypass type on a 4 for two years and have substantially reduced warmup times. I also don't run an oil cooler but use a heat exchanger, the coolant keeps my oil temp stable. This is a bit complex and I wonder at times if I should just have added radiator louvres which would also save weight but require a bit more pilot input to control?

[Hawkertech]

A note of caution, the 912 is a full flow system and most water coolant thermostats stop this flow. A bypass type allows flow at all times. I have is used a bypass type on a 4 for two years and have substantially reduced warmup times. I also don't run an oil cooler but use a heat exchanger, the coolant keeps my oil temp stable. This is a bit complex and I wonder at times if I should just have added radiator louvres which would also save weight but require a bit more pilot input to control?

I like the heat exchanger idea. The new Ford diesel trucks run oil/water or air/water heat exchangers, the latter for the turbo intercooler.

[Dorsal]

FWIW the Thermo-Bob has a built in bypass to accommodate the Rotax (and other similar cooling systems)

[efwd]

I have been considering adding something to my cooler since Im currently using aluminum tape to mask off about 1/3 of the surface area now that the temps have fallen. Unfortunately this item would be too restrictive for me as it seems to cover approx. 1/3 of cooler while in the full open position. I need every last inch of the cooler when the temps reach 90 degrees let alone the 105-110 degrees we see out in the local deserts.

[JoeRuscito]

I never ended up doing anything to mine for the same reason above. One or two strips of Al tape when the temps get down to 60 or so and that gets my oil right where I need to be for the whole winter. I will say the coolant stays kinda low and I sometimes add tape on the radiator as well. Then in the summer I like the full cooling! I would love to have adjustability beyond taking the cowl off (I cant fit my arm in the naca), but havent come up with anything I like yet. Delta Whisky (mostly him) came up with an interesting idea to trip the airflow in the naca to reduce its efficiency and maybe reduce cooling but I havent tested yet. Ill keep yall posted.

[jiott]

Several years ago I got tired of messing with aluminum tape on my oil cooler as the seasons changed and came up with a much better, easier way to do it-see the sketch below. I don't even need to remove the lower cowl; I can slip my hand in thru the lower air inlet and add or remove blocking strips as needed. I made 4 of the 1" aluminum blocking strips (the most I ever need here in Portland area is two of them); I even made a couple of 1/2" strips to fine tune it if needed. The side gripping channels are pinched down just tight enough to hold the strips in place but allow easy installation/removal. I just slip them in from the top of the channels and push the to the bottom, as many as required-takes less than 5 minutes. All material is thin approximately 0.012" aluminum.

This system has been working great for several years, but still requires adjustment as the seasons change. I am seriously thing about the ultimate solution-adjustable louvers controlled from the cockpit.
Cooler Strips.jpg