RV6A down in Seattle area

"Peter Dohm" wrote

I could probably squirm out by saying that it hadn't actually seem it,
which is true, but the fact is that I simply forgot and I stand corrected.
Tracy Crook, and his work are quite famous (especially in the RV
community) and I would really like to take a look at his installation to
see just how much radiator he needed in a tractor installation with plenty
of ram air--a good look with the pilot/builder present is sure to be
informative and I would like to hear his opinion of other installations.

His installation that I saw (he has since put a newer engine in) used two GM
air conditioner condensers as radiator, and strangely enough, that is a
pretty popular choice. I don't know if he started that trend, or if he got
the idea from someone else. I have also seen Ford 3.8's and Chevy 4.3's in
airplanes with the same setup.

As I recall, he used them parallel in the cooling line, and had them placed
directly behind the standard cowl twin inlets.

The other popular radator placements I have seen use the radiator back at
the firewall, with the top of the engine baffled off from the bottom, and
had the cooling air go past the top of the engine, through the radiator,
then into the engine compartment, then out the normal lower outlet.

I would be especially curious what he thinks about pushers with ducted
intakes because consistent cooling has been somewhat elusive in southern
Florida.

Indeed. Use of NACA type of inlets have usually failed, badly. The type of
scoop that works the best is a P-51 type of scoop, mounted above or below
the engine.

The key is to have the air flow through the radiator first, then past the
engine, (or directly out into the air) because if the air picks up engine
heat then goes through the radiator, it is sure to fail.

The other key to this type of arrangement is getting the outlet into a good
low pressure area. I have seen some that looked like the twin round inlets,
only they are the outlets. They are indeed tricky to get right, it seems.
--
Jim in NC