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View Full Version : Coolant temperatures for a Model 5



wildirishtime
12-05-2011, 12:44 AM
I've seen a ton of questions about coolant temps but they always lack information on how much TAPING or LOUVERS were required to get those temps.....

For those of you with Model 5/6/7 smooth cowl 912S engines,
how much taping does it take to get into the 180-190 degree oil
and coolant realm when it's 45 degreesF outside?

I currently get 180 oil 180 coolant at 45degrees with about 1/4 of
my oil cooler (with themostat) and 1/4 of my radiator taped up.

Also curious if the group thinks the above temps are still too cold for
winter operations in Oregon?

Thanks!
~Wild

kitfox2009
12-05-2011, 08:04 AM
G`day Wild
Since installing a coolant thermostat on my Vixen (912UL) it seems to be much easier to maintain oil temps at 200F. Warmup time is also much faster. Right now with temps around freezing I have the oil cooler about 80% taped over. The coolant is 180F.
Don

kmach
12-05-2011, 08:41 AM
I am going to be watching this post closely.

I too would like to keep the temps up on the oil and coolant, it's - 4 F here this morning !
I am considering installing a cockpit controllable cowl flap to control the cowl exit air.
I will do tests first with oil thermostat and coolant inline thermostat and tape over the oil cooler and possibly coolant rad ( can't get at coolant rad with cowls on)

Looking forward to seeing what people are getting for numbers ; Kevin

Monocock
12-05-2011, 10:32 AM
On my Outback (smooth cowl 912S) I am getting 180 oil and 160 coolant with no tape over either radiator/cooler with an OAT of 45 degrees F. When OAT's are nearer 75F, they are 200 and 170 respectively.

I plan to tape up 1/4 of my oil cooler soon as winter properly sets in to maintain 200 (oil) if possible. I'm not fussed where the coolant temps are as long as they are between 150 and 190 that's fine with me.

Out of interest, is it critical to get the oil past 212F to boil off any condensation in the oil or will temps of 180 still do that?

wildirishtime
12-05-2011, 02:09 PM
Don (kitfox2009) are you saying the coolant temperature increase
has CAUSED a notable oil temperature increase as well (regardless if
this is done thru a coolant thermostat or taping) i'm curious if this relationship is always true???

kitfox2009
12-05-2011, 02:38 PM
Wild
All I know is that since installing the thermostat (and always maintaining 180F) it seems to be much easier to get the oil temp up. Last year I tried rad shutters and tape but was never able to regulate coolant temps properly. It has not been really cold here yet (about-5F on a cold day) but so far the thermostat seems to have made a big difference. By the time I taxi for T/O the engine is in the green.
Don

kitfox2009
12-05-2011, 02:40 PM
Sorry. that should be -5C.

Av8r3400
12-05-2011, 03:22 PM
I've been told by the guys at LEAF that the oil must get to 180° F in order to evaporate moisture out of it. 212° would 'boil' out the water, but getting to 180° will thoroughly 'evaporate' the water condensate out.

For the record, I don't run an oil cooler on my 912UL (round cowl) and will usually see 220-230° oil temp in the summer (~80° OAT) and 180-200° in the winter, ski flying (10-30° OAT). If you are running the MX-4T Mobil oil, your oil temp redline is 280°.

Dave S
12-05-2011, 04:21 PM
Wild,

We have a smooth cowl 7 with the rotax 912ULS (100hp)

Summer oil temp holds 220 to 240 - mostly @ cruising around 220 - 225 - higher on climb out.

When it gets below OAT 45 F I tape over 1/3 to 1/2 of the oil cooler with "500 mph" tape:cool:

When it gets below OAT 35 F and stays there I tape over the whole oil cooler and that keeps it around 215 - 230 - I can pretty much leave the oil cooler taped over for 5 months:mad:.

The Oil thermostat or adjustable shutter (like cowl flaps for the oil cooler) would be great - but my roll of "500 mph" tape is already paid for and will probably last me 150 years:D.

Just another thought to throw out - I have a friend with the same engine in another type of experimental - he has an insulating blanket that he wraps around the oil tank in the winter - remember the oil tank is designed to be a radiator for the oil system and it sheds a lot of heat.:)

Sincerely,

Dave S

wildirishtime
12-05-2011, 04:43 PM
Good point about the oil tank Dave - a blanket around that would be smart if you have room.

Does anyone block airflow to their heads to control their head temps, or does everyone focus on the radiator and oil cooler for this control?

My head temps are low too, so i'm just wondering if covering the rad allows for enough control.....

Monocock
12-06-2011, 02:15 AM
After reading this thread last night I went down to the hardware shop and bought some gaffer tape planning to tape off part of my oil cooler. I decided to fly for 30 mins first to see what temps I was getting (any excuse to fly....).

After about 10 mins at 4800 rpm my oil was 190 and the coolant was 160. Bearing in mind the OAT is 24f this morning I have decided to leave the gaffer tape in the toolbox.

She certainly wanted to climb this morning! 1700 fpm up to 4000 feet :D

Dorsal
07-15-2012, 04:52 AM
Wild,

We have a smooth cowl 7 with the rotax 912ULS (100hp)

Summer oil temp holds 220 to 240 - mostly @ cruising around 220 - 225 - higher on climb out.

When it gets below OAT 45 F I tape over 1/3 to 1/2 of the oil cooler with "500 mph" tape:cool:

When it gets below OAT 35 F and stays there I tape over the whole oil cooler and that keeps it around 215 - 230 - I can pretty much leave the oil cooler taped over for 5 months:mad:.

The Oil thermostat or adjustable shutter (like cowl flaps for the oil cooler) would be great - but my roll of "500 mph" tape is already paid for and will probably last me 150 years:D.

Just another thought to throw out - I have a friend with the same engine in another type of experimental - he has an insulating blanket that he wraps around the oil tank in the winter - remember the oil tank is designed to be a radiator for the oil system and it sheds a lot of heat.:)

Sincerely,

Dave S

Dave,
When you run oil temps ~230 what are you seeing for CHTs?

Dave S
07-15-2012, 06:06 AM
Dorsal,

In the summer (avg OAT 75-80F), (oil cooler not covered) if the Oil Temp is running 230, the CHT is normally running 240 - 245, minor power adjustments keep it closer to 240. This is with the waterless coolant.

Additional summer data:
Oil=160.....CHT 200
Oil=170.....CHT 220
Oil=180.....CHT 225-230
Oil= 200....CHT 240

And we have to remember there is variability due to differences between gauges in planes and differences in operating conditions.

DS

Dorsal
07-15-2012, 06:29 AM
This is helpful, thanks.

SkyPirate
04-06-2015, 01:12 PM
I had to tape up my oil cooler this past week end, I left about 3/4" exposed..temp ran at 190 unless I was climbing OAT was in am 29F degrees..day topped off at 55 F degrees,..140F without the oil cooler taped

SkyPirate
04-06-2015, 03:19 PM
a little ingenuity and someone could make one like this..but...the tape is allot easier :)

Av8r3400
04-06-2015, 04:13 PM
Lowell at Highwing used to carry shutters. Maybe he still has something...?

kitfox2009
04-06-2015, 06:05 PM
A couple of years ago when I was winter flying I wrapped the oil tank with a battery blanket.
Plugged it in a few hours before flying .I believe it helped with warm up as well.
Don