Oil temperature

[mocfly]

Roger,

On the first leg of my trip to osh the plane ran top of the yellow on oil temp and top of the green on CHT, made really good time from Cha to ASW via bowling green

Parked it and waited about 2-2.5 hours for some weather to go thru and after TO it slowly creeped up to and then over the red on both the CHT and the oil temp oil pressure was at min.

Question is with the same oat and da how can it act so different on the same trip?

I tried to do my best to keep the temps off the peg and came up short. Hence the landing at fondulac.

[S3flyer]

There's a revision to the Rotax Operating Fluids SI (Service Instruction SI-912-016/914-019) which has something that has probably always been there in Section 6 but I can't recall reading:

 

1. Keep the motor oil temperature below 120 C (250 F) over most of the operating period.

 

My engine has always fit this and engine oil temp has only hit yellow a handful of times. CHT hit yellow once after sitting on a 100+F tarmac for most of the day. Highest since was 225.

 

The highest I've ever had my oil was 250F on a climb out from Tulsa where ground temperatures had cooled to 102F. OAT didn't cool below 90F until 4500'. Cruised in the high 230's.

 

I used to be a bit nervous when getting into the 'high green' area and/or touching the yellow. Rereading the docs has made me realize that my Rotax is doing just fine.

 

Sometimes I think we, or at least me, over analyze all the data we have availble in our LSAs and don't really convert the 'data' to 'information'. Fixating on a single number doesn't really tell us that much. Unless, of course, that number is not 'normal' for your particular plane.

 

I'll leave it to the real mechanics to let us know if the SI has any material changes.

[mocfly]

I have to agree that I tend to over analyze, it's the engineer in me. Those that work with me and for me would probably describe my need to understand/analyze data in more colorful way.

 

With a common theme that grounds are finicky on this aircraft, one would think that a finite solution could be arrived at.

 

I am curious why Rotax doesn't measure the actual water temperature at the tank rather than the way it's currently configured.

 

Better yet, how about a setup that measures flow and temperature. Now that would be pretty trick.

 

 

 

Any opinions?

[Roger Lee]

You can put a coolant temp probe in. It's just our planes and many others don't have one installed. The main reason you don't need one is because the coolant only cools our heads so the temp is within a few degrees. For the most part if you have a CHT you know fairly close what the coolant temp is. If it cooled the entire block then that would make it different.

 

The nice thing about the Dynon D120 is it has info. The bad thing about the Dynon D120 is it has info and not everyone knows how to interpret that info and how each correlates to the other.

[S3flyer]

The nice thing about the Dynon D120 is it has info. The bad thing about the Dynon D120 is it has info and not everyone knows how to interpret that info and how each correlates to the other

 

Agreed. I try to use the word 'data' for the raw EMS numbers and 'infomation' for interpretation of data (a.k.a the correlation of the data). Same concept I try to impart in the workplace when presented with stacks of beautiful charts and graphs but no real interpretation.