SonexBuilders.net

Hello Everyone,

As the temperatures finally warm up, I have a question for all of you AeroVee operators. What do you all see for your oil temperatures in climb or cruise?

I’m just curious; my new cowling does not have the lower oil cooler hole anymore, so all oil cooling is now accomplished by the top mounted cooler. It’s not hot in Ohio yet but when it’s 60 degrees on the surface, I am seeing 220 degree oil temps in a climb and 210 in cruise. Pressure is great so I’m not worried but I do wonder what my oil temps will be when it gets hot!

I’m just curious what you all see. Thanks!

Hi, Mike:

Remind me, are these new cylinders or is this all the run-in parts minus the turbo? Even in the summer I generally don't see oil temps over 200. I did some extensive work at on point, to try to get my cylinder head temps down. My oil temps have generally never been a problem. But a cool engine of course generally has cooler oil.

I moved from the bottom-mounted oil cooler to the top mounted 2 years ago. I've seen a little higher oil temps (10 deg or so), but again generally not over 200. I still have the lower cowl opening, but I block it up with a cover plate. The plate I use in the winter fully covers the opening. The one I use in the warm months has a 1/2" hole in the center of it. I don't know if it's necessary, but I think Sonex recommends keeping some air moving under the oil sump.

Here on my Kitlog site I documented how I got my cylinder head temps down. Maybe they help translate into cooler oil temps, too.
http://www.mykitlog.com/users/display_l ... 932&row=11

My oil pressures run around 45-51psi in flight (before one of my re-builds I only got 35 psi and everything still worked fine).

Hey Mike,

Great question! This engine is a total rebuild after my idiot move last April which resulted in a light prop strike. The only items that aren't new is the crankcase, cam shaft, and some accessories. Virtually the entire engine now has 12 hours on it.

I also installed the new style horizontal cowling with no "smiley" hole in the bottom cowling. I can't help but wonder how much of this "high temp" issue is simply no airflow over the outside of the sensor. Even at those oil temps, my pressure is 48-55 psi in cruise so I'm really happy overall. In cruise my CHT's range from 300-320 degrees; even in climb the highest CHT I see is maybe 360-370 maximum.

Thanks Mike!

Yeah, then I wonder about the sensor temp. Any way to plug a sensor somewhere else in the oil system? There are two different ports to locate the OP sender, so maybe a sensor can be plugged in to the unused one? I don't recall the thread size for the OP sender?
https://www.jegs.com/i/JEGS/555/41362/1 ... gL9mvD_BwE
or
https://vwparts.aircooled.net/Oil-Tempe ... ick-t1.htm

On the bright side, my engine has never run better since I rebuilt it after MY prop strike! I'll cross my fingers for you!

Agreed Mike! I love the way my engine is running! These new heads that Sonex is now selling are gold!

Originally I had my oil temp probe on the bottom of the sump on the sump cover plate but I now have the extended sump; not sure if I can use that location again or not. I’ll have to look into that.

I’ve got a couple of other ideas as well that may help. Plus things will probably cool off more as I keep running the engine.

Thanks Mike! Hope to see you at AirVenture this year!

No more MOFOCO heads? What are they now?

I have eight hours on my AeroVee with the smiley face cowl opening. However it is fully covered with an aluminum plate with three evenly spaced 3/4" holes (subject to correction after I get to the hangar to verify hole size). Just last week with air temps in the sixties, I had the center hole open and oil temps were 180-190. I suspect even with summer temps I'll never need the full opening. The holes are plugged as required with plastic snap-in covers from Ace Hardware aviation dept.

My #1 cylinder temp are now under control after replacing the black rubber baffle seal at the back of the cowl, with the red rubber stuff from Aircraft Spruce. There is a post in my photo album, page 16, with a picture.

Also, I think my AeroVee is running great although I don't have another one nearby to compare it. I'm using the K&N washable air filter and the 2.5 needle. Other pilots around the airport say it sounds good, but loud.

They now use (at least as of the delivery of our engine kit last summer) Empi heads.

MichaelFarley56 wrote:Originally I had my oil temp probe on the bottom of the sump on the sump cover plate but I now have the extended sump; not sure if I can use that location again or not. I’ll have to look into that.

I'm not familiar with the extended sump. Where is your OT probe now? I drilled and tapped my sump plate for a quick-drain valve, so tapping another hole is always an option.

MichaelFarley56 wrote:Thanks Mike! Hope to see you at AirVenture this year!

I'm planning to fly my Sonex there again. Just a short 900 mile hop from Boston (I go around the lake) :-)

If you look on page 11 of the turbo upgrade manual, they show a reccomended location for the oil temp probe if the sump hols is already used. It is on the red blockoff plate on the lower left front of the engine. It also has the advantage of putting the probe where it does not have to be dealt with durring oil changed.
Jerry