Oil Temperature Control

[Andre]

I think the basic problem in 14 is that oils are running too cold in our northern climate. We have a heat switch what starts the fan, but we dont have a thermostat to adjust the lower end of the oil temperature.
That is why I have partly covered my oil cooler in cold seasons( you can find this from owners manual).
In future I will fit a Mocal thermostat to the oil lines to control the oil temperature.

@T 24 Have you installed that thermostat yet?

Riding with low oil temp will cause oil dilution and possibly sludge. Drag is increased as well. All things not desirable. At current ambient temps I am lucky to get to 60°. Even in season it takes a while to get the engine up to temp.

Are there any trade offs with a thermostat like oil pressure and reduced flow (when it has opened up of cause)?

[Andre]

Found a couple of images that gives me a good idea as to my pressure and flow questions.

The first one (Mocal) does not have a bypass and appears to block 100% until it starts to open.

The second bypasses 90% until it starts to open while always letting 10% through in order to avoid air pockets and sudden changes of temperatures in the engine.

[T 24]

I have not installed that thermostat yet. At the moment I have -14 degrees celcius in my garage, so the motivation is not too high..
I also will change a higher lift exhaust camshaft and bigger(440 cc) secondary injectors to plenum. But this fu..... winter.

[Andre]

Currently a balmy 3°C here. Still not motivated to hang out in the garage.

I see you got a different Mocal thermostat than I was looking at. Of cause you have different part and mounting considerations with your setup than most 14 owners

[Andre]

On to continue my monologue. 

The first one (Mocal) does not have a bypass and appears to block 100% until it starts to open.]The first one (Mocal) does not have a bypass and appears to block 100% until it starts to open

.

This is incorrect as I found out. It does have a bypass (duh) and it lets a  certain percentage into the cooler when "cold".

Reading abouts in the light aircraft forums on the ROTAX engine. These aircraft guys are picky. 

The ROTAX is a boxer motor with up to 1352 cm3 and  135 hp. They have seen problems with oil thermostats. Engine oil temp remains below operating temp in the winter and gets uncomfortably hot in the summer. Reasons for this were that in bypass mode the thermostat let too much oil flow into the cooler and in full open mode only 90% of the flow was achieved. Problem was solved with a thermostat designed to open at higher temp and larger build (higher flow).

[grog]

i cant possibly understand your cold temps but can totally understand getting up to operating temp via thermostat. all cars use them, some have two. what would you think is a good operating temp? most cars run coolant 100 to 110 degrees, under pressure. tonight i rode home, quickly in around 30 degree c, temp gauge and electronic thermometer both said just over 60c. oil temp. hot days , over 40, ive never seen above 90. my fan is worn out by never coming on. yes, it does work, i checked. ambient must make a big diff. to the fuel ratio on 14, if you dyno and set at at 20, is it much diff at 30. sensors for air i realise. my real question, spend bucks to dyno, pc3, 5 degrees here in winter, 45 in summer. is the dyno set up changing much because of temp.

[Andre]

Ambient temperature makes a big difference. At 5° my fuel consumption is much higher than at 20°. I guesstimate that A/F is quite high. Ambient as well as engine temps are used to set A/F. By getting engine temp to operating temp we should get a leaner mix even in the cold. What is a good operating temp IMO? Disregarding all other aspects it needs to be high enough to get rid of water and gasoline-blow-by in the oil. For that the oil should be 100°C (boiling point of water at sea level). Certainly a little less than that will suffice but takes longer. I set 80° at the screw-in thermometer as my minimum. Measuring at the oil exit port (to the cooler) is the best place to measure oil temp IMO. Currently looking at a thermostat rated at 93° as that should (guesstimate) give a temp of 100° at said exit point.

For now I am tending towards MISHIMOTO IN-LINE OIL THERMOSTAT MODEL: MMOP-EXTFC https://www.mishimoto.eu/mishimoto-in-line-thermostat.html  and upgrading to 93° https://www.mishimoto.eu/mishimoto-sandwich-plate-replacement-thermostat-93degc-200f.html

I like its design and its size. (For the way it is mounted on the 14: Width 10 cm, Depth 3.3 cm. Length (least critical) 5.2 cm. It's M20x1.5 - AN 10 fitting suits as it indicates that there will be sufficient throughput to avoid flow-drop. If I am  not mistaken, the fittings needed for the original oil cooler and the engine-side fittings are AN 8. Plenty of adapter there to make it fit.

Changing engine oil will be more involved as the temp while you do it is likely below the threshhold for the thermostat to open. You will have to drain and fill the cooler separately. Without this mod most of the oil in the cooler will empty. I assume that the original behemoth holds 300 to 500 cc. Our cooler's performance is great, which is good and bad. With the thermostat it will be only good. That's my thinking and I have faith.

Since talking about leaner, a side note towards another mod I am preparing for: I am going to make the A/F richer on the cheap but not by way of keeping the engine below my target temp. Save some, then loose some fuel efficiency. Well, different topic.

[Andre]

if you dyno and set at at 20, is it much diff at 30. sensors for air i realise. my real question, spend bucks to dyno, pc3, 5 degrees here in winter, 45 in summer. is the dyno set up changing much because of temp.

Have read recommendation to run different maps for summer/winter (even with autotune for the PC!). With the future mod I plan in conjunction with some other things (hopefully all on the cheap), I will not need different maps or PC at all. I'll find out when I am all done and had a run on the dyno (just for checking the A/F). Won't be an hp/Nm monster but it will be interesting to see what the mods will do to performance.

[T 24]

1:About the oil temperature: In pilot boats we use 15w 40 diesel oils and recommendable running temperature to oil is 80°c-110°c for self cleaning reasons (dilution and sludge, as you mentioned Andre). 14 is running mostly too cold in northern Europe.

2:About winter/summer maps: I have noticed, that my 14 runs much too rich under +10°c (also earlier with N/A engine).

African model, perhaps.

[Andre]

Under +10° temps is when I get concerned. Times were so much simpler when I had my 1st K2. All service done by the dealership and no screw-in thermometer. I am glad I don't have her anymore. Rode her hard everyday to work, including on below freezing days. Took around 12 minutes one way which takes me 32 minutes nowadays. If I would have kept her she'd likely be a piece of junk now. Hope she is having a good live in southern Spain

Will be interesting to see what effect the Mocal thermostat will have on the A/F. Hope less icy temps will come and get you motivated to spend time in the garage.

[black14]

grog said "my fan is worn out by never coming on"

Mine too!! I've ridden in temperatures up to 47C (a lot hotter than that waiting at an intersection in full sun sitting between a couple of trucks!) and the fan has never come on.

I too thought something amiss, but no - fan works fine so unless whatever triggers it is k-nackered I guess it's not getting too hot...

To be honest, even if the fan did come on I can't see it cooling at all effectively...

[KiwiCol]

I've had my fan come on (once) with the bike idling for a long time in the garage, no air flow over the motor. Can't remember what I was doing at the time either, was ages ago.

[T 24]

My fan started once, after several hard pulls on dyno, and my thermometer was over 100°C. And my front mudguard melted.

[Andre]

My fan started once, after several hard pulls on dyno, and my thermometer was over 100°C. And my front mudguard melted.

Best line I have read about fan coming on