High Climb Out Oil Temps

[bucko]

I just returned from Colorado and experienced high oil temps on climb outs (especially at high altitude airports). Would see 220's and ended up doing step climbs: 120 MPH IAS (not knots) with EGT's about 1,250.

 

1965 M20--E with I/O 360.

 

CHT's were all about 320-340, except for #3 which maxed out at about 374.

 

Going to LOP at altitude, oil temp back down to 196-199. All CHT's were lower, with #3 about 354.
(Please, no LOP vs ROP discussions- I go from fuel flow of 10 down to 8 gph with LOP losing only 3 knots TAS, and all my temps are better).

 

What EGT should I climb out at? Any other suggestions for management of climb out high oil temps? Oil levels were normal, and oil change done prior to the trip. (So it was new and clean.)

 

Also, JPI matches old Mooney oil temp guage still in original cluster.

 

I did read the article on "Target EGT" found at http://www.advancedpilot.com/tech.html , but was unsure as to how to calculate it for my E model.  Looking at the chart for the M20-J, it looked like about 1,325 degrees.

 

Any comments or insights would be appreciated.

 

Bucko Strehlow
M20-E

[Hank]

Target EGT is easy, and requires no calculating.

 

On takeoff as close to sealevel as possible [my old home was 567 msl, that worked just fine], rotate, raise gear and take a quick peek at your EGT. That number, whatever it is, is your Target EGT.

 

For takeoff and climb thereafter, lean to that Target number and you'll do fine. I would not trust the EGT number from another aircraft, much less a different model. Too many variables, sensor type/location, baffling style/condition, etc.

 

The Target should hold for varying field elevation, DA, loading, etc.

[Andy95W]

It sounds like you have a pretty normal IO-360.

220's is a bit high for oil temperature, but the green arc goes to 225, so temporary 220's at hot/high elevations should probably be expected.

EGT is only tangentially related to oil temp. EGT can raise CHT which would then subtly raise oil temp, but your CHTs are really good, so that's pretty doubtful as to cause.

Oil temp is really all about airflow. Climbing at 120-130 MPH (unless you need Vx or Vy for some specific reason) should probably be your norm. There is a thread here about climbing at Vz, which roughly equates to Carson speed (about 136), for efficiency.

The cowling mods are supposed to help airflow through the engine compartment. I noticed a slight (very slight) decrease in CHT and oil temp after installing the LASAR cowl closure.

[Ragsf15e]

Bucko - 

 

I had a very similar experience in Denver earlier this year with my new to me M20F.  It was about 8,000' DA, so I leaned prior to takeoff, but I didn't know exactly how much to lean it.  Took off with it too close to "max power" and quickly got ~425 on the CHTs and ~220 on the oil temp.  I have a JPI930, so I could see it all happening pretty quickly.  I increased mixture and all the temps fell right back down toward a normal climb.  

 

Since then I've played with the "target EGT" method on other high DA takeoffs and found ~1250-1300 EGT works for my plane.  When leaning prior to takeoff, I can get the EGT up to about 1450 or so, but then I enrich it back to 1250-1300.  Climb temps work out just fine.  I'd encourage you to try this technique and see what target EGTs work for your setup.  Like the previous posts said, this temp should be somewhere around the sea level, full rich takeoff EGT.

 

Good Luck!

Rags