Leon Promet wrote:

Hi Paul,

Thanks for the reply.  I'd never even considered the "Plugs Up" config
until I started researching homebuilt aircraft.  Being a tinkerer, I'm
going to try it in the next race car.  See we have steering boxes on the
right.  I can run the exhaust out the left side of the car where there is
plenty of room and away from the tootsies.  It also gets the turbo away
from the inlet manifold,  and balances the engine left to right in the car.
 With a decent turbo hanging off an engine,  there is a decided weight bias
on the right side.

Assume for the moment you can handle all the drain back and cooling passage issues.
Is this a drag car or a road racing car? The distance from the
outside of the exhaust and intake manifolds to the e-shaft center line 
is greater than from the bottom of the engine to the e-shaft center line.
It may not line up with the transmission input shaft. If you raise the transmission
and engine you will raise the CG which is not a good thing for a road racing car.
It could be a good thing for a drag car depending on the class.

You will still have to hang the turbo on one side or on top of the engine.
You cannot put it under the engine for the above CG reason.
You also need to put the turbo above the oil sump level for proper
turbo oil system drain back. Send me a scale drawing of what you have in mind
or just a sketch and I will do a scale drawing for you.
Sounds like an interesting car.

And I'd be using a dry sump anyway,  which brings me to the main issue.
 OK,  I know you are highly skilled and knowledgeable.  so a couple of more
questions please if I may about oil pickup arrangements for a rotary
aerobatic engine.

Assuming I build and RV6A,  and I want to do mild aerobatics (I'm 52 so I
don't want to do competition stuff),  what ideas do you have about inverted
flight and vertical flight oil supply.  .

You will need a complete dry sump system for sustained inverted flight.
I would have to study the oil drain back system in very close detail
but it does not look good internally for sustained inverted flight.

I'm of course very familiar with the dry sump techniques on racing rotaries
and other comp motors (I've had experience both the factory style and
Weaver Bros style dry sump pumps).  I'm also familiar with the Christen
System as used on Lycomings (I know a bloke who has a Pitts), but I am
having trouble getting my head around how to apply this to a rotary engine.

It seems to me that with  a 350 BHP turbo rotary in an RV6A  and the right
prop,  you could almost stand the sucker on it's tail.  That's OK. I can
easily devise a system for this.  However,  when inverted,  the front
counter weight will be immersed in oil which will aerate it terribly, and
the centre housing will fill up as well.  This would seem to require an
efficient dry sump scavenge system.  This then requires a swirl
pot/de-aerator container,  which is a gravity device.  The ones used in
cars obviously just won't work upside down!  So I think,  maybe I'll need
to make a centrifuge style de-aerator.  It's all starting to get too
complicated,  and I hear my the voice of one of my mentors;

"Keep it Simple Stupid!"

I'm flummoxed.  Any ideas.

Best wishes and kindest regards,

Leon Promet

This is a cut away of the center housing. The oil drain back problem does not look
too bad here with a scavenge pump pickup on top and bottom. It is the front 
housing as you say  that really gets screwed up when
the engine is run plugs up. I need to take some detailed pictures
of the front housing oil drain areas back to illustrate this.

Paul Lamar
 
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