Perry Mick wrote:

I moved the oil cooler inboard to the armpit location and closed up the
holes in the cowl on top and bottom. Weather opened this morning so I

could

climb to 4500 feet. Cruised around at 5400 RPM, oil temp 180, coolant

temp

1/4 on the idiot Mazda gauge. 13C morning. I have never seen temps this

low

at this higher power setting. Lesson learned: do not use a 12A oil

cooler on

a 13B, even if it looks the same. Hopefully I can fly around now in the
hotter climates next summer. Attached are some photos.

Notice in the photos also, that I lowered the coolant rad leading edge,

the

air is split about 2/3 to the rad and 1/3 over the engine and finned oil
pan. The rear of the coolant rad is raised slightly to improve flow into

the

ductfan. After moving the oil cooler inboard and closing the cowl holes

I

gained another 50 RPM on climbout, 5270 now at 90 knot climb. The

ductfan

inlet seems to be very sensitive to obstructions.

Perry

Did you notice any loss or gain in top speed?

Paul Lamar

Hi all,

Perry, I would like to know what typ of cooler both mentioned oilcoolers
are:
I am a little lost with cooler-lingo, but how do they work: A tank on each
side with a couple of crosstubes or are they one/two/three tubes that wind
back and forth?

The reason why I asked is, if both are the typ with 2 tanks and crosstubes
(huge cross section, slow flow thru the cooler), it depends where the
inlet/outlet is placed and if the cooler stays full with oil when stopped.

A couple of years back (about 15 or so) I thought of putting an oil-cooler
on my BMW R100S, but got warned by some people, that if you would not bleed
it right, it would not work - it seems that both inlet and outlet where
pointing down as this was the shortest connection to the pump, the cooler
was up in front of the engine on the frame. The oil would feed into the
inlet tank and start to compress the trapped air in the cooler, so only the
one or two lowest crosstubes would feed oil to the outlet tank, waisting the
majority of the cooler on trapped air! The solution was to change the outlet
to the top so any trapped air would be pumped out. As it was it still
worked, if it was bled correctly on installation, as the oilpump would hold
the oil. However over time air would get in and the original cooler
configuration had to be bled on a regular basis.

Any chance something similar could have happened to your 12A cooler?

Thomas J.

 
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