25 hrs and still running hot.

[rjarrell]

Did my maiden voyage over a year ago and had high oil temps. For a year I followed these threads and did all the things everyone suggested. New baffle seals, RTV around them and anywhere else air could escape, new cooler, Anti splat cowl flaps, remote mount oil filter (with cooling fins) and even split the rear heater 2" scat line to blow on the filter. Tested oil temp sensor in boiling water and replaced it anyway. At this point I relocated the oil temp sensor to where it should have been all along on the adapter instead of the engine. At least Air Wolf filter relocation kit specifies to do this with their adapter, others probably do also just don't have paperwork.

Different engine but AeroSport Power IO-540, worth a try... good luck

[Randy]

To recap, my setup is IO-375, low compression, RV7A, EZ cool cowl flaps, vernatherm removed and oil plunger installed. I have checked all the normal things to check to trouble shoot high oil temps and finally put 2nd cooler in, somewhat out of frustration, and partially as an experiment to see if it would at least temporarily solve the problem, and it did. In fact I would say it did more than I expected since the oil is partially cooled before getting to the 2nd cooler the temp delta and thus cooler efficiency is not as good.

It does seem a little weird to have a 4" hole behind #4 and another 3" hole behind #3 in the rear engine baffle feeding to the coolers, oh well, for now it is a workin!

Anyway, against the advice of most anybody I talked to about my oil and engine temperature issues, I finally installed a 2nd oil cooler, and I like the results.

The 1st cooler is the 8432R dual pass cooler fed with 4" scat on RV10 firewall mount. The new 2nd cooler is an inexpensive Positech P2000C model (I think I got that right), 6 row cooler.

I have adjusted my oil pressure to run at the Aerosport specified 80 PSI at 180F and 2400RPMs.

The new cooler is mounted on the passenger side to engine mount tubes, and fed with 3" scat.

Before my temps would shoot past 200F very easily and when I tried to live with a limit of 220F I learned that the oil temps would not stabilize below that temp either.

I have oil squirters on an IO-375 so there is reason to expect about 20F increase over an engine without the squirters I am told by the tech rep at ECI.

So the results are that I can now keep the oil temps under 200F in normal flying conditions and do so fairly easily. I use the 4" butterfly valve on the first cooler to bring the temps up as needed. It sure is nice to actually use that valve for a change! It works great and the results of adjustments can be seen fairly quickly on the engine monitor. Our OATs have fallen in the last week so I have not had the chance to check it out in high OAT conditions but the difference from operating with one cooler is significant.

I am not really recommending that others take this route. As Dan H said on a previous post, something must be whacked in my install. This does at least give me another data point to learn from and I really like being able to run my engine at best power setting for long periods of time if I want to. Before the 2nd cooler I basically had to run lean of peak or way rich to keep temps where I wanted them.

Perhaps I will make a better air feed situation to my first cooler to see if I can improve things enough to eventually remove cooler #2, but for now it is letting me move on to the next big phase, paint. I had held off on this in case I needed to get some outside air to solve the problem.

If as reported, the 8432R drops oil pressure 15 PSI, and a normal cooler another 3 PSI, I may now have an 18PSI or so pressure drop across my two coolers.

I need to study the oil routing diagrams more to fully understand the effect of the pressure drop issue. Perhaps for another post...