Mod 90 Rotax Coolant Temp creeping up with OAT

[LSaupe]

After a 3+1/2 month hiatus, finally got back in the air today. Had a great flight. However, this was the first time I have flown above say 45F. It was 75F and I noticed my cruise coolant temp was a bit higher than anticipated (170F). Coolant level is full and thermostat is operating fine (opening at 140F).

This is a Kitfox III, 582 Rotax gray head with belly mounted radiator. I was hoping to see maybe 150-160F or is the 170F typical? Concern being how much worse things might get on a hotter day.

Running the recommended 50/50 mix. Less than 50 hours on all components.

Anyone run across this before?

Larry S.

[TY2068]

Sounds pretty normal and I'd expect slightly higher with higher temps.

[jiott]

Generally speaking, all things being equal such as engine load factor, your coolant and oil temp will rise equal to the ambient temp rise. This is not an exact relationship because engine efficiency changes with temperature, but its a good rule of thumb.

[Olle1975]

Hi,

everything less than 170F is ok.
During summer I got more than 170F at departure and I try to solve the problem.
First I fill in a mix with 70% water and 30% antifreeze and I saw very better temps during departure but sometimes I got temps less than 125F in flight level during colder days.
Then I mount an radio shutter and be able to set the airintake, very fine to set the temperture during flight and approach to hold the enginetemps.
At last I saw that my cooler had a little part which was'nt able to get airintake, because the part was covered by the "airoutgoing-lip" from cowling.
It was confirmed by non-insect part at the cooler, have a look at yours. I try to redirect the airflow with a sheed and it works......
I attached a few pics, I hope it could explain better than my bad english ;).

Olaf

[LSaupe]

Great pics, thanks for posting Olaf.

[TY2068]

Earlier thread covers this subject pretty well.

http://www.teamkitfox.com/Forums/showthread.php?t=1690

[LSaupe]

Hey Olaf:

I have the same window blind system to control temps. Did you get that from Highwing LLC? Sure is nice when using cabin heat or on a long decent.

I had the same airflow blockage issue and droppedlowered (using spacers) the radiator by 3/4" (further into the airstream) and that fixed the issue. I was planning to go your route or maybe even add some vortex generators, however yours looks like a cleaner mod.

[ppilotmike]

Great pics, thanks for posting Olaf.

X2. Love your your Youtube channel keep up the great work. Mike:)

[Olle1975]

Thank you very much!!!

I noticed, that I got no information about answers, but I think, I have solved the problem now :rolleyes:.

Yes, I got it from Highwing LLC :)

Regards!

Olaf