Lynn, do you know of anyone using the side ports and P Ports
for

and

 intake configuration.  I hear from different sources of poor
idle

with P

 Ports and that the power band is very narrow.  I was thinking
of

using

 the side ports and have the P Ports open above 7000 RPM.  Tom

Webber

The Pport idles quite a bit better than the bridge port. There
is

much less

overlap on the Port. You can drive it around the paddock area as

though it were

a street car. It has very little power just off idle, but it is

not

bucking

and back firing through the intake. The bridge ported engine is
a

nasty mess to

drive just off idle. The idle is set at 2,000 RPM and attempts
to

exceed that

with a load on it are met with a stalled engine or a bucking

monster,

or

both. You have to slip the clutch quite a bit to get it going

because

you need to

hold it at about 4,000 RPM. Once it is rolling fast enough,

everything is just

fine.

None of this applies to aircraft applications. The plate that

carries

the

plastic damper units is more flywheel mass than we have and it
is

at

a larger

diameter, plus the flex plate mass is a help. So right there is
a

big

improvement. Also the propeller system is a big flywheel that
can

keep things going

smoothly.

On the Vintage rotaries web site there is a fellow who has both

port

styles

in one engine and switches manifolds between the two with
manifold

flange to

bloc off the unused ports. He claims that the open volume of the

unused ports is

not a problem.
He is driving this thing (an RX-3) on the street, so he has many

hours of

operation on both setups. He no doubt has a flywheel also, so he

would not see

the problems we have. Even with no rotating mass, the Pport
idles

very smoothly.

It just doesn't like to go anywhere just off idle. A plane side

port

would be

just the same as a street car and would be great for driving

around

on the

ground.

If you build your own Pport, you could shorten the timing a bit

and

move the

torque peak down the RPM band as much as possible. Higher runner

velocity and

more torque where you need it, around 6,000 RPM.

I think that both port styles at the same time would be a waste
of

time.

Going from one to the other could be done. But it would be
curing

a

problem that I

have not seen. A fast idle to get warmed up and to the end of
the

runway, and

then a gentle shove up to full throttle, then full rudder and a

little brake,

then shove the nose back down at 50 feet and wait for 100 knots

and

a

vertical departure.

Lynn E. Hanover

Thanks Lynn,  I'm going P Ports, then  Have you ever used Racing

Beats

P Port Rotor housings?  Good, Bad? Price high but I don't have
the
skill
 to create my own.  Anyway thanks for the information.  Tom
Webber

Tom,  originally I investigated Racing Beats P ports.  A couple of
points that I want to bring  up but if they sound wrong to anyone

else,

  don't hesitate to set the record straight.   These ports are very
large and they are timed for an engine turning very high rpm.  Jim
Mederer told me they would not perform at 6000 rpm. They will not
perform at 7500 rpm either. I believe he said 10,000rpm and up.
Another point,  these are just inserts.  Not throttle bodies.
There

is

no way using the RB housings to have the butterfly right at the
port.
This is important for throttle response and idle.   Lastly,  the
ports
are bored perpendicular to the housing. Consequently, they are
angled
upward.  This makes it even  harder to get adequate intake runner
length.   At our relatively slow turning engines the runners need
to

be

around 22 inches in length for 6000 rpm. For these reasons (and
some
others) I decided to roll my own.  But I got a lot of expert help
and
advice all along the way.  At this point, I think we have the
timing,
size and shape of the ports optimized for our application.  Within
weeks we will have a nice, air worthy throttle body.  Boring the
housing is not hard to do,  but a local machinist is going to set
up

to

do a precision job at a very reasonable rate.   All this is coming
together right now.  It a few months you will be able to send in
your
housings and get them back p ported with throttle body installed.
Jerry

Jerry,

Do you have a "concept" sketch of what your final intake system
might

look like?  I've been following this closely, trying to figure out
where you
are heading with this.  My impression so far is dual throttle bodies
placed
in close proximity to the rotors, but then you mention 22" runners.
Where
do the injectors, air intake, and runners all fit in?

Bob Lemings

It will look almost identical to this Power Sport P-port manifold
that

Allan Tolle

used in 1995 to go 238 MPH in the Sun 100 race.

Paul Lamar

Hey, Jerry...I need my engine to be configured like that. I mean I
REALLY
need my engine to look like that.  Maybe you can do with less sleep
and have
them ready sooner? (only kidding).  On a serious note, I have always
admired
the neat, compact and professional looking intake setup on the
Powersport
engine. If you can duplicate that, I think that you will have a very
marketable item. Keep up the good work.  Paul Conner

Lets see if we can get Ed Klepeis interested  in producing that intake.
  It is beautiful.   How about it Ed?         Jerry

 
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