oil cooler - sensitivity to location

[prkaye]

I'm mounting my oil cooler on my left aft baffle as per the finish kit plans.
I didn't play close enough attention, and drilled the mount to the rear baffle flush with the outboard edge, instead of in by 3/8". This means the baffle is also a little lower than it could be had I located it inboard by 3/8" (since the cowl slopes up towards the center. SO this means my oil cooler doesn't have quite as much visibility to the airflow as it could. Should I replace the baffle parts and oil cooler mount (and relocate it properly) or is this not so critical?

[Scott Hersha]

Depends on your oil cooler and what engine you have. Generally, the higher you have the cooler, the better. If you have a 7 tube Stewart Warner or 13 tube cooler, it shouldn't be an issue. If you are concerned, order a new baffle piece and save yourself the hassle later. I mounted mine high on the baffle on my RV-8, O-360 with 9:1 pistons, 7 tube Stewart Warner style cooler, and my oil temp is 180-190 in normal cruise flight. You'll have to do some trimming on the outboard upper angle of the baffle support to clear the cowl, and I recommend a steel angle support on the forward side of that angle to prevent eventual cracking, but it's the simplest and most user-friendly installation for the oil cooler. I mounted my oil cooler on my first airplane (RV-6) on the firewall and oil temps, with a butterfly air restrictor, were always right at 180 degrees, winter or summer. But it took a lot of work and fabrication to make it work out. If you mount your cooler too low, it can't get enough unrestricted airflow to be efficient.

Scott