Oil temperature during cold months

H. Paul Shuch is a Light Sport Repairman with Maintenance ratings for airplanes, gliders, weight shift control, and powered parachutes, as well as an independent Rotax Maintenance Technician at the Heavy Maintenance level. He holds a PhD in Air Transportation Engineering from the University of California, and serves as Director of Maintenance for AvSport of Lock Haven.

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Warmi
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Oil temperature during cold months

Postby Warmi » Mon Dec 25, 2017 1:04 pm

It got cold again and I my oil won't go above 175 F or so , even during climbs ( and it is only going to get colder.)

My understanding is that I can block the radiator a bit to limit the air flow ...

The idea is to get some aluminum tape with self-adhesive and glue one stripe across the radiator ?

https://photos.app.goo.gl/cUvxPpdMETmnhUUr2

Just wanted to confirm ... Thanks
Flying Sting S4 ( N184WA ) out of Illinois

3Dreaming
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Re: Oil temperature during cold months

Postby 3Dreaming » Mon Dec 25, 2017 9:42 pm

I already have a strip on my CT. BTW, the CT has a LOA for the installation of the tape. I am not sure about the Sting, but on the CT the oil cooler is behind the radiator. Sometimes it is a balance to get the oil temp up while not having the coolant get to warm.

Warmi
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Re: Oil temperature during cold months

Postby Warmi » Mon Dec 25, 2017 11:41 pm

I don’t have a Loa - I am actually surprised I would need one just to cover a bit of radiator :D

Right now , my cruise oil temps are about 170-175 F and CHTs are about the same ( maybe 5-10 degrees difference ).
When getting ready to land , after descending to the pattern altitude , it drops down to about 160-165 for oil with a similar drop for CHT.

Not sure if this is a reasonable range for flying during winter months - my EFIS EMT doesn’t complain but I remember reading that the oil should be kept around 190F - I would prefer not to tape it since I lack LOA but not sure what else to do ...
Flying Sting S4 ( N184WA ) out of Illinois

3Dreaming
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Re: Oil temperature during cold months

Postby 3Dreaming » Tue Dec 26, 2017 10:19 am

Tape it and don't look back. You need to get your oil temp up above that 190 mark for at least a portion of your flight. Don't worry about the coolant temp being too cool, only too hot. I only mentioned that Flight Design issued an approval to show that measures like that are needed and recognized by some of the manufacturers. Stop by a heating and cooling shop that does install work, and see if they have a roll that is almost empty that they will let you have cheap. I like the kind where you have to remove the backing to stick it down. It seems to stick better, but not to tightly. Don't use duct tape it will leave a gooey mess.

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Re: Oil temperature during cold months

Postby Wm.Ince » Tue Dec 26, 2017 11:16 am

3Dreaming wrote:Stop by a heating and cooling shop that does install work, and see if they have a roll that is almost empty that they will let you have cheap. I like the kind where you have to remove the backing to stick it down. It seems to stick better, but not to tightly. Don't use duct tape it will leave a gooey mess.

I use aluminum tape from HD Aviation Suppy (Home Depot). It works very, very well and does not leave any residue behind after being removed. Get the kind that has a removable "brown" backing. It is what FlyingMonkey recommended to me a few years back, and it works great.
Bill Ince
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drseti
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Re: Oil temperature during cold months

Postby drseti » Tue Dec 26, 2017 12:49 pm

Warmi wrote:I don’t have a Loa - I am actually surprised I would need one just to cover a bit of radiator :D


Why are you suprised? ASTM rules that require an LoA to change brands of battery, tires, or light bulbs surely wouldn't allow you to do anything as drastic as applying tape, without an LoA!

The best solution, IMHO, is an oil thermostat. These are standard on some installations, available options on others, and just plain not allowed on some. Best time to install one is during Rotax 5-year rubber replacement. (Of course, if your SLSA didn't come with an oil thermostat, it will most assuredly require an LoA to install one - and after installation, an oil system pressure purge is absolutely necessary.)
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
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AvSport.org
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Warmi
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Re: Oil temperature during cold months

Postby Warmi » Tue Dec 26, 2017 1:16 pm

Thanks.
I will look into installing a thermostat - Sting MEL specifies 3 options including Permacool and BilletPump so no LOA required ...
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Oil temperature during cold months

Postby drseti » Tue Dec 26, 2017 1:25 pm

FWIW, both of my SportStars came from the factory with oil thermostats, and for the one SportCruiser in which I installed one, the manufacturer was fine with providing an LoA. In any case, this time of year I always recommend a good engine preheat. Here's a link to one you can easily and inexpensively build (and it requires no LoA!)

http://www.avsport.org/publicat/nonfict/preheat.pdf
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
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AvSport LLC, KLHV
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3Dreaming
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Re: Oil temperature during cold months

Postby 3Dreaming » Tue Dec 26, 2017 1:46 pm

A thermostat alone might not do it. My CT came from the factory with a thermostat, and still needs the tape to get the temperature up.

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Jim Hardin
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Re: Oil temperature during cold months

Postby Jim Hardin » Wed Dec 27, 2017 8:14 am

Curious...

Where is the heat being directed in the cowling?

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drseti
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Re: Oil temperature during cold months

Postby drseti » Wed Dec 27, 2017 9:04 am

Directly at the engine block. But with the blanket thrown over the cowling, the whole engine bay ends up reasonably warm. You can use a non contact IR thermometer to see hot spots and cold spots.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
fly@AvSport.org
AvSport.org
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3Dreaming
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Re: Oil temperature during cold months

Postby 3Dreaming » Wed Dec 27, 2017 9:59 am

Paul, one suggestion for your heater. Get it up off the ground. If you have a fuel leak the vapors will be close to the ground, and the heat gun can ignite them.

I have a home made heater for my CT. It is built out of a $15 space heater from Walmart. I have 2 4" hoses coming off of it. One hose has a reducer that plugs into the front of the cowling where the duct goes up over the cylinders. I stick the other hose in the oil door. I made a second one for use around the airport. It is mounted on a hand cart from Harbor Freight. My 14 year old son made the plenum that the hoses connect to. I still want to add an extension cord and electrical outlet to the cart to support a battery charger.

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Re: Oil temperature during cold months

Postby drseti » Wed Dec 27, 2017 10:14 am

3Dreaming wrote:Paul, one suggestion for your heater. Get it up off the ground. If you have a fuel leak the vapors will be close to the ground, and the heat gun can ignite


I agree, Tom - and that's exactly what I said in the article! ;)
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
Prof H Paul Shuch
PhD CFII DPE LSRM-A/GL/WS/PPC iRMT
AvSport LLC, KLHV
fly@AvSport.org
AvSport.org
facebook.com/SportFlying
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MrMorden
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Re: Oil temperature during cold months

Postby MrMorden » Wed Dec 27, 2017 10:41 am

Using tape is a fine art. I often find I use too little or too much, and then I end up with my temps too high when I climb or too cool in cruise. Yesterday with 32°F OAT was a "too cool" day. Oil temps around 180°F most of the time so I went into a steep WOT climb to 6500ft to get the temps up. That worked well and got me to 220°F. But now I had another problem, I had to get back down! Even on a very shallow descent, the oil temp went down as low as 140°F before I got back down to ~2500ft. At least I got the oil temp up for a bit, but I can't imagine big temp swings like that are ultimately good for the engine.
Andy Walker
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akroguy
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Re: Oil temperature during cold months

Postby akroguy » Wed Dec 27, 2017 11:36 am

For less than arctic conditions, just a drop light with 60 to 100Watt bulb tucked into the cowling with a blanket thrown over works fine.


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