> > > >>  >>> rotary engine tuner. And that is this. The diameter
of the pipe also

 > > >>  >>> affects
 > > >>  >>> the tuned length. Surprise! Have you been to
 > church lately and seen
 > > >>  >>> an organ?

 Paul, I would think your points on tuning should be beaten into
everybody. The point on the Lemans engine is that to make it
tractable enough for A RACING CAR which will often compromise
drivability for power they still used the variable length intake!
The ports on the engine are LARGE the diameter of the intake tube
and the short length prove tuning for probably 8500-9000 rpm as
well. Finally the rotary is a ported engine. (duh) Any change in
port height is a timing change, both exhaust and intake.

The 2 cycle racing engines I used to work on were dramatically
effected by small port changes. Even
the entry angle was CRITICAL. This is of course apples and oranges,
however, small port timing
changes WILL effect your performance. Sometimes working in areas you
do not expect, like preventing
the engine from running through a certain rpm. (say around
3500-4000) The exhaust systems bends we
must put into our systems to make them work are also a major tuning
factor, they are very
 > inportant to the standing waves and overall efficiency. Paul I
know you know these things but often amature tuners will dive in
where engineers fear to tread, with good reason! Bill Jepson

Bill,   I am one of those overly bold amature tuners.  I am not
worried about the overall problem of boring the ports or building
the intakes but that a subtle discrepancy in timing may screw up
everything.  I don't know how to find out what I don't know, except
the hard way.  After I post the drawing of the leman port, I am
hoping that some real engineers will look at the timing, overlap and
so on.   Jerry

 
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