RV6A down in Seattle area

"Morgans" wrote in message
...

"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.

I think that you may mean heater cores, which would have a larger water
passage, but I am hoping for a look if I go to SnF this year. The layout
that you mention is very similar to one that I have seen used successfully
on a Subaru conversion in a KR2--although I don't know who may have done it
first.


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.

I think that you are essentially correct, although I don't know how much of
the problem is engine compartment heating and how much is poorly organized
airflow if the air must flow past the engine.


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.

Tricky seems to be an understatement, especially when using airports that
demand an estended ground run!

--
Jim in NC

Peter