Chris (Gentry), you should design to drain the turbo oil into the pan by
gravity. In my case, my TO4 turbo was about 1" above the oil level and

about  a

12 " run. I used a 5/8" ID drain oil line that proved to be inadequate.

I knew

it was inadequate because I was getting some light smoking out the

exhaust. Like

you, I had very little room to work with. I added an electric pulse type
scavenge pump which works in parallel with the gravity drain that I got

from

NAPA which solved the problem. It is a possible that the pump will fail,

but the

turbo will drain adequately without it.

I would not have done this if my oil level was at the same heigth, or

above the

turbo drain, because it would likely overheat the turbo bearings because

you

would then be pressurizing the drain line. Also, don't forget you can't

run the

drainline uphill-it needs to slope down the entire length.
Chuck

Chris Gentry wrote:

Thanks for the input Chuck,  Sounds like good advice.  I plan to fabricate a
new aluminum oil pan that will have more horizontal area for oil. This means
the total oil in the engine pan will be the same but oil depth will be
lower, hence more turbo drain drop.  I have calculated that the oil pickup
depth will always have a supply of oil at this new level. If after trying
this method I encounter smoke I will then install a Napa fuel pump in
parallel.  Chuck, do you have the Napa part number for the pump you are
using?  Also do you know how much current it draws?  How many hours do you
have on that Napa pump?  Do you switch the pump on and off from the cockpit
or do you run it constantly?  I may go ahead and install the pump you
suggest anyway. The reason I have considered doing that is I may temporarily
turn on the pump prior to doing any maneuvers and/or aerobatics.  Then off
in level flight (cruise).
 Regards, Chris Gentry
                Glasair Turbo Rotary
                 Dragonfly Turbo Subaru
                  Grumman Cheetah

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