A question for Ed or Tracy:
What size AN fittings did you guys use for your A/C evaporators, and
what
size for the remote oil filter mount? I saw the $100 price for the
remote oil
filter setup from Racing beat and decided to make one from the existing
oil
filter mount. I just removed it and tapped a 1/4 npt into the holes, and
made
a plate to cover the mounting boss with 1/4 npt holes where the oil
passages
are. Total cost so far- $0.Just wanted to know what size lines to run
to the
oil filter and oil cooler. I'm figuring on two A/C evaporators running
in
parallel, with AN 10 fittings-- is that what you guys used? Thanks a
lot.
Brian Trubee
Redmond, Wa
Tracy Crook wrote:
I did not use AN fittings on the evaporator cores in the interest of
economy. Just welded aluminum pipes (with hose retaining bead at end) and
stress relieved with a fiberglass & epoxy fillet at junction of tank & tube.
Inlets are 5/8", outlets are 3/4". Cores are connected in parallel. I
don't compromise on the high pressure oil lines so I used aircraft SS
braided lines and AN-10 fittings. This is the size adapters available for
the 13B and Mazda oil cooler so I would recommend staying with -10 here.
BTW, with the duct changes to my oil cooler and getting the muffler out of
the cowl, I have a new cooling problem to solve. The oil temp would not go
over 180 deg. in climb (on 80 deg day) and stayed below 160 in cruise which
is too cold. Water and oil temps are now the same (oil was 15 - 20 deg
higher than water before changes). Keep in mind that the water is measured
at the hottest point and oil at the coolest so this is not quite as wierd as
it sounds. I'm going to reconfigure my cooling outlet for lower drag and
install a controllable air valve to control temperature.
In general, I have a lot of work to do on drag reduction. I was talking to
a local RV-6 builder who has the second fastest RV-6 at 238 MPH (behind
Tracy Sailor) and got some interesting insights. When I asked him how he
learned the best way to improve drag, he told me the best thing he learned
was to ignore the aeronautical sacred cows and start looking at the
airplanes that go fast (he goes to all the Reno races). As an example, he
pointed out his wing intersection fairings. He doesn't have any, just a
flush fit with a tiny rubber gap seal. My plane has large wing intersection
fairings designed using the results of some NACA study on intersection drag.
They look cool but he said if I wanted to go fast I should remove them. I'm
going to try this and a bunch of other things he pointed out.
Tracy Crook
rws@altavista.net
www.rotaryaviation.com
Come on Tracy quit slandering the engineers. You are one :-)
Some guy told me those root fairing work better at high altitude
hence higher angles of attack hence higher lift coefs. More
skin friction at high speed lower angles of attack.
They are a trade off. I buy that. Why do you think heavily loaded
747 have them and jet fighters don't?
Paul Lamar
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