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?

[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.
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[Dorsal]

Don't know the make of the oil thermostat but I believe it is the one KF sells. The coolant unit in the picture is a Thermo-Bob. Oil temp runs about 185 (plus or minus 2) and CHT (hotter) sits at 202-204, very steady at cruise.

[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)

[Lawdog]

Don't know the make of the oil thermostat but I believe it is the one KF sells. The coolant unit in the picture is a Thermo-Bob. Oil temp runs about 185 (plus or minus 2) and CHT (hotter) sits at 202-204, very steady at cruise.
Thank you. I like that set up

[JoeRuscito]

Has anyone tried to make an adjustable cowl flap of some type? Considering my water and oil temps are low I'm wondering if this might be a nice adjustable solution for all weather/temps.

Can someone enlighten me as to what is a min except able water temp on the 912 is?

As for oil I've been told 180 F is acceptable as long as you get it up above 212 F every once in a while.

Thanks all...Lots to learn.

[HighWing]

About 15 years ago, I helped a guy finish a Series 5. His plan was to take it to Alaska. He wanted some method to manage the temps. We decided to put a NACA flap on the opening to the radiator and oil cooler. We did the deed and he moved on, sadly, I lost contact with him and can't give any reports of how it worked, but the attached pictures gives an idea of what the mechanics looked like. I have no pictures of the duct cover itself, though. The forward hinge on the duct cover was the fiberglass cowl skin itself and was left intact as the opening was cut to expose the cooling apparatus.

[JoeRuscito]

What a cool idea! I love that the skin just remains as is (before cut) when closed. Really nice thinking!

[Shadowrider]

So we where running heat exchanger water/oil and they would keep both temps within 10F of each other. We installed new high flow oil pumps and discovered the heat ex-changers where limiting oil flow so we removed them. Now coolant is much cooler now and its hard to stay warm, in the cabin. We have our oil coolers completely covered and the CHTs are around 140f.

Joe did you come up with a solution?

[avidflyer]

I recently installed a Thermo-Bob 1 in my Kitfox 4/912. The thermostat is 180degree, seems to have helped keep the coolant temps higher and my cockpit heater makes heat now. JImChuk

[Shadowrider]

I was looking at that. I guess the fear is if the thermostat fails closed? I guess they have been around awhile do they have a good track record?

[4Hummer]

I've been eyeballing these units on eBay for the Oil Cooler, and would like to do something similar to the Coolant Rad

Opened

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Closed
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[Meyer]

Timely, I need something too.

[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.

[Shadowrider]

Seems like like those running the oil thermostats seem to work good at keeping the oil where it needs to be. Why do most not run the oil thermostats? Wondering if you ran a oil thermostat for the coolant also because they allow continued circulation?

[jiott]

I have had the oil thermostat for 7 years and all it seems to do is speed up the winter warm-up time somewhat. It seems to do nothing for the winter over-cooling problem, so I still need to block of part of the cooler face as the seasons change. Here is how I do it to make it a little quicker and easier:

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.
https://teamkitfox.com/Forums/attachment.php?attachmentid=23906&d=1579635914&thumb=1 (https://teamkitfox.com/Forums/attachment.php?attachmentid=23906&d=1579635914)

[Shadowrider]

Thanks Jim. I currently are doing something similar to what you are doing. I was contemplating on putting in an oil thermostat, but sounds like I will still be covering up the oil cooler. We currently have to cover the entire oil cooler to get to temp in the winter and the coolant is still cool. 130f. In the summer I was running half of my oil cooler covered. Just trying to figure out solution that does not need so much tinkering.

[Shadowrider]

Well I have contemplated putting in an oil thermostat and a coolant thermostat but I have decided I am going to make a shutter. We have plenty of cooling in the summer. Warmest temps I only uncovered half of my oil cooler so I think a shutter would be fine with it covering up a large percentage of the cooler when its fully open. Someone gave us a shutter that goes on a 0-360 oil cooler, but it needs to be about double the width. I think its made by https://antisplataero.com/products/oil-cooler-air-shutter Right now I think its easy enough for me to draw it up in solid works and find someone to cut it out for us. Anyone else know how to use solidwork in case I get stuck?

[Eric Page]

Anyone else know how to use solidwork in case I get stuck?
There's lots of free SolidWorks help available on the EAA forum, here (http://eaaforums.org/forumdisplay.php?27-SOLIDWORKS).

[JoeRuscito]

Yup SW is what I do. Happy to help if you get stuck.

[Frontier Fox]

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When building Frontier Fox I decided to use a shutter instead of an oil thermostat. In pic one notice that the oil cooler brackets were left longer and bent 90 degrees to accommodate a channel for the slats to be mounted on. Pic two shows one of slats attached to a stainless rod. It is hysoled and riveted. Pic three shows everything assembled and in the open position. Note the bushings that the rods pass through. Pic four shows the shutters closed. The control cable has a stop on it to prevent the rack from going over center. Pic five shows the control knob. In for open, out for closed. Sorry about the sideways pictures, maybe someone can fix that.

[Shadowrider]

Nice! That is some handy fab work. I like how it has less restrictions when open.

[Eric Page]

Sorry about the sideways pictures, maybe someone can fix that.
I've found that many of the photos I take with my iPhone upload to the forum sideways, and no amount of rotating them from the Windows context menu will prevent it. The only solution I've found is to open the picture in an image editing program (doesn't seem to matter which one), then save it again. Once I do that, it uploads in the correct orientation.

Don't get me started on vBulletin forums' handling of images... :mad:

[jiott]

Joe's cooler louver fab work is top notch! I have seen it in person.

[rtc183]

I made a simple bended piece of aluminum that I just pressure fit into the NACA inlet. I had to cut out the hole in the middle to adjust how much air got to the oil cooler. It works great and is super easy to make. I put tape on it to keep it from scratching the cowling.
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[4Hummer]

Note the bushings that the rods pass through.

Brilliant !

You have a part number or a name for those bushings ?

Also what is this attached to? must slide somehow ?
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[Frontier Fox]

4hummer
Here is the Amazon link for the bushings:Hobbypark 12pcs 02101 Steering Plate C-Hub Bushing Sleeves for Redcat HSP HPI Bullet MT 3.0 WR8 Flux (https://www.amazon.com/gp/product/B01N3OQEO7/ref=ppx_yo_tab_ap_asin_title_o00__s00?ie=UTF8&psc=1)
The piece of aluminum that all of the rods are connected to does not slide in anything. All of the rods connect to it and the end of the cable. Hope that makes sense. I am still in Phase 1 but so far the shutter has worked well. I close it to warm up the oil and coolant faster and open it a little as needed. Still playing with it to hit the sweet spot in colder temps.

[Maverick]

It would sure be nice to have scale plans for that louver system. Hint, hint.

[Frontier Fox]

I wish I could help you with that. My drawing skill are that of a third grader. My technique is to think what needs to happen, measure, think it over for a few days, then start building. I write down a few notes on my steel bench with soap stone Page through my blog for more pics, it really wasn’t that hard to do but was time consuming.