Paul I don't want to be the source of discouragement to anyone so feel free to
post this or not.

First up. Nice drawings. I was wondering how I was going to model it.  Yes
I
think we are pretty much in agreement now.  A few differences in terms and
ID sizes. I happen to think a wee bit bigger ID is the way to go.

A press fit in my thinking doesn't necessarily mean a hydraulic press fit.
Of course distortion is to be avoided. If the hole and insert are round the
you can do a slip press fit with a small tolerances (.002"?) and a very
cold
insert. I suspect even a  good fit may even move a thousand of an inch
during heating and cooling cycles.  This is a good thing I believe. Cary
and
a few others  have already done press fit with a tap of hammer.  That is
most likely because it is difficult to get it to go straight in.  A slight
bevel on the front edge would help.  As Scallawag says if you get it cold
enough you shouldn't need to heat the housing.  He recommends not to
because
of warpage potential.  How to get it real cold?  Dry ice in a foam box, or
liquid nitrogen. The later is not available at your neighborhood
supermarket
I know.
Yes all tubes and pipes are not completely round and so the insert needs
lathe work. I would machine a step on the end that holds the flange as well
to get a nice weld.  The housing port will have to be finished off, ground
and polished in any case. It seems this is a given in P-ports.  There are
ways to do this and precautions to take and the info is out there.

I do see where you are coming from design wise as it solves the gap
challenge and that you still have high regards for the JB Weld to act as
sealant.  I don't think anyone can  say how long it will hold up in an
airplane engine.  That it works in auto racing engines is proven without a
doubt. These engines take a lot of short term abuse but don't endure
thousands of hours of hot cold cycles.  I'm not trying to discourage the
P-port effort in any way.  Au contraire. Safety is on my mind. Who wants to
rebuild engines even though they are easy to do so.  I would rather be
flying with it. P-ports make a lot of sense for our airplanes.  That and
the
adjustable length manifold are great innovations.

Keeping the insert in place is not a design challenge. Finding the best
material to seal the inside housings but stay flexible is. Machine a step
on
the insert to rest against the stubs and it won't be falling into the
engine. Counter sinking  set screws drilled and installed in the remaining
two stubs on each side of the tube will hold it from coming out as the
steel
bites into the soft aluminum. Look at how the exhaust port is kept in place
and you can see what I mean.  Add to the holding force is the sealant.
You can pour the port full but why?  Smeared around  the insert and hole
before placement is adequate.  Put some more around the pipe perimeter
after
pipe insertion and then do a water test.  Water leaks will be easy to see
where if indeed there are any with a tight fit.  Is more sealing better not
necessarily.  It is a mind set we do to make ourselves feel better.

O-rings are best for side sealing purposes but NG on our desired straight
in
approach into a curved housing.  I wonder what else is flexible but a
literal pain in the ass to remove from aluminum housings and comes in two
part liquid form as well with many hardness options to choose from. Hint
you
use it to make molds for high temperature plastic forms with undercut
reliefs. 

No picture came through about the potential leak area. I would be
interested
to see that as I must have missed it.

I don't have access to the machine shop down the road now because they are
assembling some top secret industrial equipment for Epsom/Seiko. It looks
like a machine used in an assembly line plant for flat panel displays.
Seiko gets a little worried to see a non employee working in the factory
and
threw their weight around.  A-holes.  Paranoid I might steal one of their
ideas.  Actually they stole one of my research groups idea we brought to
them (our stupidity) to make 25 years ago.  It was a wrist watch that had a
device in the band that sensed and displayed heart beat.  They patented it.

Justice was done .... sort of.  They spent a fortune trying to market it
and
lost the fortune.   Moral: Only let your rivals steal your bad ideas:)

That leaves me with a good drill press at the moment and a chopper circuit
to control the speed.  The insert I will order out.

DougFir

Darn. Too bad! That machine shop was one hell of  a resource for you.
Is this the 1990's SAE paper you referred to above.

Paul Lamar ...No rotor no motor.

Paul

About the SAE paper I think the one referred to is different. It is best you
refer to page 20 at the above mentioned RX-7 site.  Posting the data here
will just confuse everyone.  Again I concur racing ports shapes and aircraft
engine shapes have different design goals.

One question.  When boring through the housing how much of the lower
bolt hole housing do you go through?  None ? just graze it? Halfway?

Here is a post from the same site I thought you would enjoy.


"If you want to make a big precise hole in aluminum there is an easy way if
you have the tools.
1- center drill (no flexing in the tool that will determine the placement of
the port)
2- use your hole saw, a smaller one though, like 1/8" under what the final
hole should be.
3.1- I make my own boring tools, It's easy as hell, take a 1" or greater
steel round
3.2- turn one end down so it fits in the chuck or collet of your machinery
3.3- cross drill a 3/8" hole in the other end of the 1" round
3.4- cross drill and tap another hole in the round that intersects the 3/8"
hole
3.5- take a broken 3/8" tap and walk to your bench grinder (it's a hard
metal and makes good cutters.
3.6- grind away until the thing is shorter than your hole dia (plenty of
clearance)
3.7- now grind a cutting edge into what's left of the tap (I know kind of
unclear)
It should look similar to a cutter for a lathe
3.8- stick your cutter into the 3/8" hole you drilled earlier and secure it
with a set screw in
the hole you tapped earlier.
3.9- chuck this boring bit into your machine and make a hole a few thou
under desired
so the final pass just cleans it up and makes a nice surface.
My dad is an old tool maker and he taught me this, we have a half dozen
different sizes lying around the shop.
The end result should be way more precise than the hole saw method and
should hold the sleeve a lot better. I can't imagine the surface is smooth
with a hole saw, the more rough the less surface area and less holding
force.
Making the tool might take an hour but it will make a perfect big damn
hole."


Doug Fir

That is funny. No mention of the required mill or lathe
rigid enough to hold the cutting tool and the rotor housing
in precise alignment due to the tremendous forces involved.
You want to know why a good mill weighs 7000 pounds?
It is because there is no substitute for lots of cast
iron when it comes to rigidity.

Heck if you own a mill or lathe you can afford a $60 Chinese
boring head. You are not going to do this on a drill press.
I should not say that as you might try and be successful :)

"One question.  When boring through the housing how much of the
lower bolt hole housing do you go through?
None ? just graze it? Halfway?"

I am not sure I understand the question. OK I think I know
what you are saying. You are talking about the lower TENSION bolt
hole just below the p-port bore.

We go through quite a bit of it but we don't break through
the bolt hole. See the attached scale Mazda DWG.
We split the difference at 8.640 inches up from the
bottom. The Lemans engine uses the same tension bolt
pattern as the 13B and RX8 engines.

You have hit precisely on the problem of using a tube greater
than 2 inch OD. I think you just talked your way out of it:)
The problem did not occur to me until you just found it :)


Paul Lamar ...No rotor no motor.

I have not read every silly page but as far as I know
nobody has equaled the 172 HP per NA rotor Mazda got.
These guys are talking 150 HP per NA rotor.

Kenku may be Japanese but he lives in Wisconsin.

Doug, you seem bent on the rest-of-your-life R&D program
so why don't you try something like this :)
I may have these lying around someplace.
Ken Powell and I put our heads together on this.
I drew them up and built them.
You want a good idle with a p-port. Here it is.

Paul Lamar ...No rotor no motor.

Paul,


Yes on the R&D life work but, sorry not the rotary engine. Its 'cleaner
energy research' which has snagged me:). IMHO all ICE are going the way of
the dinosaurs ironically because they depended on them.  The Wankel is such
a nice dinosaur though. To bad its won't have a chance to live a full life.

I've have actually building the airplane part of the equation right along
you know.  Nice idea on the adjustable P-port timing mechanism but not sure
of the benefits and I couldn't imagine how to make it without constructing a
special housing from scratch. Sorry I'll have to pass on this one.  Even
your JB Weld wouldn't be up to the challenge:)

Believe it or not a good smooth idle is not a big concern of mine. What
always has concerned me is achieving the best BSFC at cruise speed, and
cooling the engine.  Your advice therefore on the aerodynamics of cooling
and intake systems is priceless.  My last concern before boring the test
engine housings are  the slide throttle placement and injectors and manifold
taps come into play on the decision.  Remember I will run ethanol.  Shooting
it in the bell mouths will create a nice refrigerator in the intake manifold
and I believe may cause an increase in droplet size or condensation.

Here is what the guys making AGE 85 in South Dakota Univ. are saying lately.
They  "installed an Airflow Performance fuel injection system to compare
with the stock Bendix system" after they put 700 hours of testing on the
airplane running both fuels.


Press Releases

Mooney: Airborne Again.
Thursday, May 11, 2006 10:45 AM
The engine modifications and overhaul have been completed. 25 hours have
been flown in order to allow for a proper engine break-in period. Initial
results indicate more horsepower, better fuel efficiency and cooler engine
temperatures. After replicating the fuel efficiency test flights from before
the modifications, the next phase of testing is detonation performance of
the 10:1 piston modification. AVL equipment from the Seneca is currently
being installed and testing should begin shortly. A modified Light Speed
Engineering Plasma III CDI ignition system has been installed, which gives
the pilot the ability to vary ignition timing from the cockpit during
flight. This feature will allow for multiple timing points to be tested in
one flight and thus enable a better understanding of the effects of timing
on detonation.

Doug Fir

It is a small world. Interesting that they are using Klaus's
"Plasma" ignition system. Maybe they believe it :)

I think you  need to turbo charge without an inter cooler
and direct inject the alcohol into the compression chamber after
the P-port closes to cool the charge. An inter cooler is
basically an energy drain wasting the heat of the charge.

Paul Lamar ...No rotor no motor.

Paul

Yes on Copperstate on Saturday.  I probably won't have time to fly to Santa
Paula first as I am coming in to Sacto on the 25th resting a day and then
flying to Flagstaff on the 27th.  I'll be arriving in Casa Grande on
Saturday morning and leaving Sunday so I'll see you there with the pump.
That will make a good prop for your lecture as well.


Two 750cc injectors in the housings probably won't not deliver enough fuel
to get to 300hp. on take-off  Especially if the fuel is ethanol.  This was
the main reason (4 injectors per manifold) I considered a horizontal slide
throttle and cast aluminum elbow with two more injectors. That and it is
easy to encased the lower injectors in a box that goes from the housing to
the slide throttle.

Perhaps lost wax for a few units is possible.  Collecting beer cans now..

Doug Fir

The direct injection takes max advantage of the alcohol's
unique ability to cool off the charge. It also insures that
no un burned fuel goes directly out the exhaust down
past the rotor face.

There is nothing wrong
with four injectors up there. Point them in horizontally.
RB  did that on the land speed record 3rd gen RX7
three rotor with three turbo chargers along with an ice
water intercooler. (268 MPH)