Oil Cooler Airflow Splitter

Somewhere along the line, someone smarter than me figured out that the airflow through the standard airbox wasn't being evenly distributed through the oil cooler.  The large SCAT tube comes down into the box, and then the air has to turn 90 degrees to flow through the cooler and escape. By using some tepmerature probes they found that the top of the cooler was being cooled differently than the bottom of the cooler. This led to a fix, which is just a simple vane inserted and riveted into the air box to split the air into 2 chambers, forcing it to flow through both the top and bottom of the cooler more evenly.

There is a kit available from Airflow Systems, as a purchaseable aftermarket mod that you can do. A friend of mine and fellow builder had them send me a kit. In the end I decided to fabricate my own, to get it to mount a little higher in the airbox (i.e. I made the part a little taller), but I used very slightly thinner material to allow me to flex it better to get it to fit through the opening for riveting. They also include a couple pieces of aluminum angle for you to cut and make brackets out of, but again I had plenty of scrap so I cut my own. Using this I was able to twist and bend the thing enough to insert it into the airbox, for match drilling and clecoing with the aluminum angles.  It was quite a chore to get it all fit in and drilled, but after a few hours I had it in place. I used pop rivets in the very hard to reach areas, but flush rivets countersunk in the accessible areas.

In the end, it didn't do anything noticeable to lower the overall oil temps, but I'm guessing that the temperature of the cooler itself is a little more even. That was just results from an initial test flown at 3000-3500msl, which isn't all that common for me, so if I learn more later I'll update this page.

Update 2010: I am still using this thing in my oil cooler box, but I think if anything, my temps are now running higher than before.  I now easily get over 190-195 in cruise where I was usually 185-187.  In climb I now will hit 220 where I wouldn't have before.  So I'm not sure if this one was one that I'd recommend just doing "just because".  Definitely study up on this one and maybe do some other things like add the better oil cooler before you take this step.


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