> This also accounts for another anomaly I've noticed over the years.
It
> seemed like the water cooling was slightly better on the first flight
> after
> topping off the system.  I was never sure because the next flight was
> usually on a different day, different temperature, humidity, etc.  Now
> that
> I've been paying close attention I have verified that only a few
ounces
> worth of air in the system makes a noticible degredation in cooling
> performance  (about 5 degrees worth).   Not sure why this is happening
> either but I'm happy with the results.  With more experimentation the
> answer
> will probably come out.
>
> Tracy Crook
> tcrook@rotaryaviation.com
> www.rotaryaviation.com
Tracy,
FWIW, the 93+FD owners have known this for years. Just a little air
screws up the cooling system performance big time. They even have
elaborate procedures to "burp" the systems to get rid of all air.
Sometimes it takes all afternoon to get all the air out of a system. And
these systems use an entrained air bubble remover 'swirl pot' as well to
vent out the bubbles before the system is connected to the overflow
tank. Of course the positions of all the components may have
necessitated some of the components. On the attached pic I put an arrow
pointing at the "swirl pot" (with the .9 bar cap). You can see the
tubing from the other pump cap to it. From the bottom of the swirl pot
additional tubes route to the expansion tank.
[Marc Wiese]