Paul, This is a composite of what my pressure traces look like at
5000 rpm. This is from a side-port intake and peripheral exhaust
rotary. I added the combustion trace for reference. The system I use
can record 50K/sec and the data becomes very dynamic.... the pressure
peaks seem to slowly increase and there position retreats about 80
degrees between 3000 and 8000 rpm.

Barry Bordes

I am not sure what I am looking at here but there appears to be
something seriously wrong with that engine. I suspect one or more
apex seals are leaking. Good engines are more consistent.

Take some pictures of where the pressure sensors are located.

Please load that first picture into MS Paint and label the lines.
Which one is intake and which one is exhaust?

What brand of data acq are you using?

The first two pictures are yours. The rest I took on a P-port. The
sensors were looking at the apex seal oil holes in the rotor
housing.

I just installed an exhaust pressure sensor on the TTC engine so if
all goes well I will have some data on that.


Paul Lamar

Paul, My focus was on overlap pressures in the area between the
ports. The intake sensor is plumbed at the front plate opposite the
secondary port itself. The exhaust was first tapped into the exhaust
sleeve area but because of a weak signal was moved to the EGT port on
the exhaust pipe 2" from the flange.

The system is by TFX Engine Technology http://www.tfxngine.com/

The pressure sensors for intake and exhaust are non-TFX.  (TFX
sensors are $1000 each). I am using GM MAP sensors and have attempted
to scale them properly for the charts. The taller trace is the
intake.

Do you do Face Time?  I could show you the program results live.
Barry Bordes


That is very interesting to me Barry. I have always wondered what
went on in that area. Due to the bath tub depression in the face of
the rotor there will always be some over lap. I suspect the inertia
of the gases enter  into the successful functioning of the rotary.
The analogy is a turbo jet engine.

The inertia of the gases exiting the compressor section cause them to
flow into the combustion chamber. If one looks at it strictly from a
pressure point of view that may  be misleading. I would love to see a
flow visualization in that area.

So little is known about what actually goes on inside a Wankel.

What we need is glass Wankel  with a pulse of high pressure colored
gas applied to the spark plug hole at the right time.

There is a free idea for you Simon Saba :-)


I don't do Face Time. What is it?

Paul Lamar


Paul, with FaceTime if you have common iPhones you can talk with
video for free. My wife talks with her sister in England no charge.

Maybe my best bet would be to make a video and send it to you.

Back to the overlap reversion... the best way to port the exhaust
is to do things that help the bottom of it flow but leave the stock
anti-reversion steps in the top of the port.

The exhaust sleeves and your 20 B have another approach....
by separating the top and bottom of the exhaust.

With the combustion testing... the best verified success was
an experiment for speeding the burn rate. I had to take 2° of
advance out of the timing after the modification to get the peak
pressure located back to the proper 45° ATDC.
Barry Bordes



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