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Guys I have been struggling with lower oil temps than I would like. 90+ day 3000 msl cruising at 2650 rpm cht 275-295 Egt 1200-1270 . At those settings my cruising oil temps would be 160 and any decent (500 fpm at 2300rpm) it quickly falls to 130-140. I put a Steve rance TOCA on and it would only open in a hard wot climb to 3k ft. It was still cruising at 160. So I put a sheet metal cover over the sump fins all the way down to about 2” of the bottom of the sump. With this cover my temps came up. My wot climb to 3k msl got me to about 218. My cruise yesterday oat 94 was sitting 196-205 with mostly 202 all other parameters as above. I feel pretty good about those numbers although they are 5-10 more than ideal. Needing opinions because that’s a large change from my “normal”. Also has anyone else covered the Jabiru sump fins in an attractive way? Sheet metal painted black is ok but not attractive in my mind. Engine is a solid lifter 3300. Any ideas would help. I was trying to avoid cowling work but may have to go there.

Mark,

I don't think your oil temps are all that bad. 160 deg F is a bit low, but not excessively. I try to run my oil around 180, and I use 200 as my desired upper limit for normal ops. I've been testing my oil at every oil change and the lab hasn't noted any excessive acidic tendency (suggesting that the water is in fact being boiled off at these temps). I think you might be good leaving it as it is.

Jeff

Are you certain that your temperatures are indicating correctly? It seems that many Jabiru 3300 owners will try to bring oil temps up only when it's pretty cold (below 40 degrees F). If it's 90 F on the ramp, it's a battle for me to keep it out of the high yellow range while climbing or even at high cruise rpm at lower altitudes.

Yesterday, it was 88 F at 1500' AGL and I was in the yellow trying to keep up with my friend in his Swift running about 2950 rpm.

My oil cooler is weepy these days so maybe its lost some efficiency.

Guys, thanks for the reply’s. I have an oil/water separator that when disconnected I find some condensation in the vent tube leading me to my desire for oil temps high enough to boil out the water. I had good psi at the 200 temp range of 47-50 psi. When I am pushing 130 at cruise in the winter with half my oil cooler intake taped off and it only comes up to 160 without tape in 94 degree days I guess I just kinda figured I needed higher temps to keep moisture out. I’m putting about 80 hrs a yr on it though so at least the oil is getting moved around regularly. The TOCA won’t even open until 180 so. All my cooling on my first run was without the oil cooler even open until I was almost at 3000 msl. Once I leveled off it dropped back down into the 160-170 range so the cooler was bypassed at that point. I got responses that 160 wasn’t too low but nobody said 205 was too high. Book stated continuous 212 max oil temp. I may modify the cover to allow a little air on the fins and see if I can get it down to 190 ish. Thanks again at least I feel more confident in the lower temp numbers now

Have similar setup and found same result. Assuming your Jab is one of the Gen 3 or earlier with ribs on front of the sump. I have found it best to partially close off the standard Sonex inlet that is under the prop, and have added a new inlet on one side of center hinge joint, just ahead of the oil cooler. The air over front sump fins provides too much cooling, especially in winter when I close the standard inlet completely, and airflow to the cooler lets Steve's TOCA do its thing.

David A.