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What is your rising oil temps on climb out procedure.

Redbud40

Well Known Member
Ok it’s that time of year again. Just curious what others do if you see the temps rising on climb out to the high normal to pushing caution range. Cruise also.
Any go to procedures?
 
How hot is it actually getting?

Mine will rise to about 230 on a hot day with a long climb, but will stabilize around there. I don’t worry about it at that temp. Usually about the time it starts getting hot is about the same time I’m high enough that I have cool air coming into the oil cooler.

If I need it to cool, then I need to level off, reduce power and wait several minutes. It’s pretty rare that I have to do that.
 
Similar. I think I saw 225. But it was only 93 OAT today. I was more curious as to what others do if anything in preparation for the 100 degree days approaching rapidly.
 
Look back to NACA papers in the golden age of aircraft piston engine development, and you'll find this nugget...cooling demand is proportional to mass flow.

Since the engine is a fixed displacement air pump, mass flow is proportional to RPM. So, to reduce cooling demand, first reduce RPM.
 
I generally cruise climb to avoid high oil temps. When I was flying out of Inyokern, I'd regularly see 210 on the oil temp, but a 120 kt cruise climb would keep both the cylinders and oil happy, so that was my only gameplan.

Takeoff, accelerate in the climb to 120kts, then cruise climb at 120kts to the top of climb.
 
I can keep it at about 180 on climb all the way to 10k but I have a 9 rib cooler and 2 cowl flaps, I also cruise climb at 120kts. Fixed pitch prop, I use as much fuel as possible on the climb, I notice the CHTs will tend to climb first and then the oil temp will follow. If I notice the CHT going up, I adjust as needed. I like to keep them at no more than 410 on a climb.
 
Oil Temps

Flying in one of the hottest areas in the US has taught me a few things in nearly 2000 hours of RV time. 1) Oil temps are going to go up on climb. Reducing climb a couple of hundred FPM will lower the temps. They key is where they stabilize on level flight. With my 390 powered 7 cruise flight will give me 185 degrees across a wide spectrum of altitudes. I don't worry about temps over 230 because I know they are transient. FYI, RV 10 oil cooler with 4" scat induction.

2) CHT's. I know people who will go apoplectic if their CHT's exceed 400 degrees. With that thought, Phx area RV's would be parked from May to October. Again, the key is where they lie in cruise flight. Getting to 430 or even to 450 during a climb is not a big deal as long as it goes down quickly after level out. Even in our hot temps getting to 425 is unusual. I am running a plenum.
 
Oil temperatures....

I know a cure: get an RV-4! :D:D:D As mentioned several days ago we have problems getting our oil temperature UP! Not sure why the -4s usually don't have cooling issues of any kind including CHT.... GREAT design, is why.....
 
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