Here it is again.

Since Mazda is thinking of running the engine up side down in the new car
soon to be introduced I was thinking of the best rotation for use in an
aircraft.

That has to be with the exhaust port pointing down.
That gets the exhaust heat out of the cowl as soon as possible. The problem
with the stock center housing is rotor cooling oil drain back in that
orientation. In early days I fought against it for that reason.

Also an off the shelf dual throat Webber 52 mm down draft carb can be used
with a p-port in a very simple manor. That allows moving the engine up 2
inches.  More on this shortly.

Here is a cut away center housing showing the cooling oil drain backs from
the rotors. That is the main factor the orientation of the engine.

If we are building our own aluminum center housing that should be the way to
go. No oil pan is necessary just an after market dry sump pump system. One
AN line from the bottom of the center housing can scavenge all rotor cooling
oil.

An AN dash 16 is shown in the TTC engine oil plumbing but a dash 8 would be
plenty big enough for 250 HP.

All that breather and oil filler part can be done away with in the center
housing. Greatly simplifying it.

Paul Lamar

Hi Paul, what is the history on engine pic Eng1A.JPG ?

Steve Carlisle

That goes back about 17 or 18 years. In those days they called it plugs up.
The oil pan and rotor cooling oil drain backs were big problems.

Lew Ross original Moony installation in 1973 used that orientation because
the crank angle sensor or distributor  stuck way up over the top of the
rotor housing. Later engines did away with that crank angle sensor and the
distributor of course.

Here are a couple of 3D's with the exhaust down and the dry sump oil system
with direct oil scavenging. That was Jim Mederer's idea on the TTC engine.
The dry sump is not drawn in yet. This depends on a new center housing
designed to allow the cooling oil to go straight down.

It gives a much cleaner installation with lots of room for a cooling system
on the right side of the engine. What I am most pleased with is the
possibility of using a 52 mm down draft  Webber carb or Webber copy.
This is going to make the installation much much quicker as no messing
around with a $1000  EFI. Very straight forward and reliable just like an
aircraft engine almost.

This the ball jointed universal motor mount that fits all aircraft.
Totally adjustable so the prop shaft always comes out of the center of the
hole in the cowl. Much cheaper to ship as it fits in a mailing tube. A
traditional welded motor mount requires a 3 foot cube box which shipping on
that can b several hundred dollars.


Another draw back to the stock plugs up or exhaust down is the stock oil
pump is raised making it more problematic to prime itself.


New part clarification hopefully.
See the attached jpgs of the front housing. One stock one rotated.
Also in high G maneuvers. You want to keep the pump as close to the oil
level as possible. That is the reason the Chevy
V8 is in the oil pan below the level of the oil.

That is another reason for the dry sump system. One of the pumps can be used
as the pressure pump as done on the TTC engine.

  With exhaust down there is no room for an oil pan and a down draft air
craft or automotive carb or EFI will work.

There are 14 attachments so your cell phone my not work.

Paul Lamar

Paul,

I understand and agree with the concern over CO poisoning but the question
of exhaust manifold up remians relevant. Side cowl exits could still be low
enough (or extended lower/further back) to not be a risk or (as I would like
to use a rotary on) the plane could be an open cockpit.

Muffling could still be accomplished with in the cowl depending on
application and still on top.

Envisioning even further top exhausts could be routed between the rear of
the engine and the firewall for a bottom exit. That would provide a lot of
opportunity for a muffler installation too.

So, relevant to the engine itself, what would the consequence be of having
the exhausts on top?

Regards,
Brad

Do i miss something? Why is the stock oil pump not good enough
  for a side sump or 2g's . But good enough for the p ported normal set up?

Le Roux

The term "side sump" is a misnomer. It is still a bottom sump.
If you tried to raise the oil level by raising the sump the rotor cooling
oil would not drain back.

Consequently the oil pump is moved higher and away from the oil level making
it more difficult to suck oil under high G conditions.

The oil pump in  a Chevy V8 is at the bottom of the pan under oil with a
vertical shaft driving it. There is a reason for that.

See the attached jpgs of the front housing. One stock one rotated.
Also in high G maneuvers you want to keep the pump as close to the oil level
as possible.

That is another reason for the dry sump system. One of the pumps can be used
as the pressure pump as done on the TTC engine. The dry sump pump can be
mounted much closer to the oil level and even below it as the oil reservoir
is now mounted on the fire wall.

This subject comes up over and over again for the past 16 years.

Hey if Kenichi Yamamoto wanted the plugs up he would have designed it that
way :-)

Maybe I need to write another book.  "How to Install Your Wankel"

Paul Lamar


Hi Paul,
Yep I think it would be a good move to write a book on how to install your
Wankle. I have a folder on my computer with most of the emails over the last
2 years. A book would put everything into right order. I would certainly buy
it.
Andrew. Campbell


The Rotary Engine free News Letter. Powered by Linux. If you want off the
list PLEASE let me know and I will remove  you.  ACRE NL web site.
http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas Copyright
1998-2016 All world wide rights reserved.