Tracy should confirm this but I
think you want your oil return to enter the pan above the oil level in the
pan. Otherwise you risk oil backing up in the redrive. You also risk
pressurizing the drive and possibly blowing a seal. I know in turbo installs
this is true and a return line into the pan below oil level is a definite
no-no.
I’ll let Tracy speak up if he thinks this will be a problem. I
just can’t see it as an issue with the redrive. It’s still a gravity
feed, and there isn’t any pressure. Turbo return is somewhat
different. As I understand, they always use those large diameter pipes,
because the oil gets beaten into a frothy foam by the extreme RPM of the
shaft. I have a stock oil return pipe on the way from Mazda, and it
would bolt right on, except that something from the mount will surely be in
the way. I may have to cut the pipe and reconnect it with some
hose. We’ll see. Who knows, something has to fit eventually
:-)
BTW Mike, I’ve been
thinking about you today since I’m working on my cowl. Mine is going to
be uuuuuuugly. Van is probably having nightmares now, and doesn’t even
know why yet :-)
Cheers,
Rusty
I have never returned
the oil to a point below the oil level so I have no personal experience with
that arrangement. But ---- there have been around 5 reported cases
of oil leaking past redrive oil seals when the oil return was below the oil
level in the pan. Draw your own conclusions.
I would not count on
the oil being any less "frothy" from a planetary redrive than from a
turbo. The oil chruning through all those gear teeth is likely to be
pretty well whipped up.
If you are looking
for a convienient place to return oil, drill & tap a hole
(1/4" NPT) in the "foot" of the flywheel end rotor housing on
the spark plug side. It is at the perfect height, close to the
return from the drive and away from the hot exhaust.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com