Is there any information on the website showing the timing of the intake
  and exhaust port relative to eshaft rotation? I am specifically
  interested in the overlap and the e-shaft angle at which the apex seal
  clears the exhaust port.

  Inspired by your 555 system, I have designed a simple digital converter
  to convert MAP to pulse width for controlling the injectors.  We know
  that the volumetric efficiency of the p-port at 6000rpm is 120%.
 I am  wondering how much of that 120% is represented by intake air passing
  through the chamber and out the exhaust during overlap. If this occurs
  at all, it would improve efficiency to minimize the amount of fuel
in  the bypassed air, suggesting that the injectors should be opened
after  the exhaust is at least partially closed

  Victor Roberts

  I don't have the numbers for the timing but it is exactly the
  same as the Le Mans 4 rotor.

  http://www.rotaryeng.net/Mazda_R26B_US.pdf
  http://www.rotaryeng.net/Welded-steel-p-port.html

  The numbers can be derived from the scale dwg in this last link.

  The exhaust and intake P-ports in a rotary never really close.
  In that regard it is more like a turbo jet.
  What air does not go in one chamber goes in the next.
  In a tuned rotary engine however the max pressure in
  any given (One of 3) compression chamber depends on the RPM,
  pipe length and pipe diameter.

  http://www.rotaryeng.net/Mazda-p-port-press-wave-enhanced.jpg

  The best place to measure this pressure is the apex oil injector
  holes just above the p-port intake. Of course one is not using
  these holes for oil injection. One mixes the apex oil with the fuel.

  I am coming back to the 555 system and adding a single chip
computer that  has the sole job of adjusting the mixture using a USB
port and  storing the trim data in a spread sheet format. The
program becomes  extremely  simple and easy to comprehend. Merely a
look up table in the single  chipper.

  Henry Nee came up with this great idea and people can email and
share trim  tables. Any number of trim tables can be stored in one's
PC. It also makes  editing the trim table simple as you do it in
your PC using a spread sheet  program. This should greatly speed the
tuning of your engine and similar  installations can use the same
trim table. We can put them on the web site  for rapid download.
Parameters affecting the trim are type or drag of  the airplane,
diameter and pitch of the prop, intake pipe length and gear  ratio
used. Assuming all are using a p-port.

  Paul Lamar

  Victor,   I have seen the port timing numbers in the Kenji
Yamaguchi (SP?) papers.  I think there is a link on Paul's  site
 and possibly on Craigs Rotary List site also.

george grimes



When one apex seal is between the spark plugs, the other two are at the
intake and exhaust port area of the rotor housing. They span the two ports, so
there is a lot of overlap. That is why a p-port has that distinctive brrapp-
brrapp idle quality (or lack of depending on how you view it). Also the rotor
rotating at 1/3 the e-shaft RPM allows more time in msecs for the overlap than
in a recip engine. Each cycle as in power is 270* instead of 180. That said
though the time at 6K revs is so small there will be minimal or no dilution of
the intake with exhaust gases, or intake mix going out the tail pipe.
Remember... AC engines spend a miniscule % of their run time at idle.

Dale Davies