Jerry Hey wrote:

Predictable performance is a critical part of making up a firewall
forward package for any design.    For the Tailwind,  I originally
set
the goal of 180 hp/6000 rpm with a NA 13-B.  I was told that should
be
no problem.   But exactly how does one achieve that performance?
Assuming Tracy's ignition and fuel injection,  we still have the
exhaust
system  and intake manifold design.   Also, there is the issue of
Street  Porting or even a mild PP if there is such a thing.  Can
anyone
say that if I do the following, the HP will be............?   If the
NA
rotary can deliver180 hp, then it may very well become the engine of
choice for the Tailwind.

Of course,   the recommendations have implementable.  No point in
talking about a tuned exhaust, if there is no place to put it.

  I want to go on record to the Tailwind community saying what is
possible.  I would like to provide a list of SPECIFIC
RECOMMENDATIONS
on  how to set up the engine to achieve the performance.

    Although, I have followed the debate about spinning engine faster
(and faster) to gain more hp that is not what I am talking about.
What
HP can be made at 6000 rpm?    I like this engine speed for the TW
because of the reduction ratios of Tracy's drive and  because bearing
loads are lightest at this rpm.  The Tailwind does not need more than
180hp under any circumstances.   It is a very  hot performer with an
0-320.

Jerry

Tracy has about 180 HP with long intake runners and no inserts in the
exhaust ports. His exhaust system is nothing special with a Y in the
pipe
too close to the rotor housings. Everett said the optimum individual
exhaust pipe length
is about 32 inches. Also Tracy uses the high compression rotor in a
four
port turbo engine. As I recall Bruce did some mild street porting on
the side ports. Nothing earth shaking here. No one thing made much
of a
difference. To get more or to be sure you are getting at least 180 and
probably over 200 at 6000 RPM go to peripheral ports like Power Sport.

Paul Lamar

Are there different PP profiles for different hp levels?   Also,  I
have
heard that PPs will not idle at an acceptably low level.   Using
Tracy's
drive,   around 1000 rpm idle would be the goal.  What are the
negatives
of the PP engine? Fuel comsuption, heat, reliability?     Here is one
negative:   MazdaTrix wants over $800.00 per housing. .....Jerry

Yes. Usually it is just the size of the hole. Big Leman style hole 240
HP at 6000.
Medium  Power Sport size hole 215 HP at 6000.

Is that $800.00 with the P-Port? I think you can do it yourself Jerry.
You got a nice mill and lathe. When you get set up to do it you can do
some
for the rest of us. You got a 90 degree angle plate? If not can you
make one?

I don't know what the fuel burn is running
super lean like Tracy runs his engine.

Paul Lamar

I am very interested in taking a shot at this.   Anyone know where I can
find some junk housings to practice on?    Jerry

Try MazdaTrix. 12A ought to be more common.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.
ACRE NL web site.
http://home.earthlink.net/~rotaryeng/            http://www.linux.org