The Cessna 120-140 Association Forum

My 140 with 0-200 appears to run cold. On a 50 degree day with the two lower cowl holes covered, it still will not reach 180 degrees on climb and a one hour cruise. No external oil cooler. This was great when it was 100 here, engine would stay about 180, but now that it has cooled some I am worried about it not getting warm enough. I haven’t calibrated the oil temp gauge, but after shutting down, the engine doesn’t seem like it is up to temp. Has Any one else had this problem? Do those oil jackets work? Suggestions?

Thanks

The basic rule of thumb has always been about 100 degrees over ambient temperature. If you have a blast tube on the oil screen you might see an increase by plugging it off.

Thank you Randy, I will try that.

That is interesting (0-200 running cold) I have the exact opposite issue. My 0-200 runs warm oil temps. In the summer when it's 80-90 degrees (here in Sunny Michigan) I run about 190+ on the oil temp, sometimes 200. This is after I filled every crack and crevice in the baffling, put on an F&M oil filter, added a blast tube to the cowling for the oil screen housing and put on a larger than stock cowling lip. Yes the oil temp guage is accurate.

I'm guessing you have a 46 cowling on the front? That seems to make a significant difference. The 46 has a much larger air outlet at the bottom and seems to move alot more air.

If you don't get your oil temp back up closer to 180, let us know, there are other things to try.

Yup, ‘46. I don’t feel comfortable blocking intakes for fear I may get hot cylinders (no cht gauges). But I read that running cold is not good either. Engine has high compressions, oil filter, rebuilt about 300 hrs ago by competent mechanic. I just want to make it last. I will follow Randy.s advice and perhaps calibrate oil temp sender.

6352 wrote: ↑Sat Dec 01, 2018 7:14 pm...and perhaps calibrate oil temp sender.

Do that first, so you don't end up wasting your time... (or overheating your engine!)

Thanks John and Randy- Great forum here,

What is the “magic” number? My c85 w 0-200 crank etc ran 125 part way home shutting just lower cowl holes, and just shy of 150 once we blocked oil cooler hole under cowl. I too should get oil temp gauge calibrated.

Ray

8322 wrote: ↑Sun Dec 02, 2018 2:32 pm What is the “magic” number?

About 180. You want the oil hot enough that it reaches the boiling point of water inside the engine to ensure that moisture from combustion gets evaporated.

A typical C120/140 with good baffling will run about 100 degrees above ambient. So, when the outside temperature is below about 80 you have to start cutting back on the cooling to maintain 180. Of course, note of this means anything unless you know how accurate the gauge is.

6643 wrote: ↑Sun Dec 02, 2018 6:17 pm

8322 wrote: ↑Sun Dec 02, 2018 2:32 pm What is the “magic” number?

Of course, note of this means anything unless you know how accurate the gauge is.

How difficult (expensive) is it to get them calibrated...?