Notice the length of the pipe on the piston engine was

50 inches

long for 2500 RPM and the optimum length on the Le Mans engine for 6000

RPM

was 16 inches long.

We are nowhere near a workable theory for rotary engines. I am just

pointing out

some similarities with piston engines. Don't try to read something into

this that

is not there.  All of this is empirical. Determined by extensive
experiment on one piston engine of a given bore and stroke. The work done

by Taylor

is sure to scale only to piston engines. You keep sounding like you are

going to come

with a magical number for the pipe diameter and length. We have a long way

to go

to come up with a workable theory for rotary engines. Forget it. The only

way you are

going to do that is by extensive experimentation on a dyno. Build the

dyno.

Why bother anyway? The solution is staring you in the face. Mazda has done

it for

you. Nobody anywhere has a built a rotary engine with something other
than 2 inch p-port pipes that comes close to the 240 HP at 6000 RPM

achieved by the

the Le Mans engine. Copy the Le Mans engine exactly. What is it about this

that is

so hard to understand.


BTW Why mess with a ancient 12A engine? It is no lighter than a 13B.

Paul Lamar

One of the major differences involved with intake tuning for a Wankel is the
shape
and duration of the "suction" pulse as related to the frequency of those
pulses.

The Wankel case is analogous to hooking all the intakes to a single pipe
for a 3 cylinder piston four stroke.  This probably has the effect of
reducing
the "sharpness" of the resonant peak. Obviously tuning works, as evidenced
by the Le Mans engine. Resonant devices are characterized by a "Q" factor
of resonant efficiency - the opposite of damping. Both "organ pipe" modes
and cavity modes (Helmholtz cavities) can be used to support resonance
(or disonance - untuned wave damping") . 

If you look at the ranks in a pipe
organ you can see that length/diameter ratios are a factor in the "Q". A short
length to diameter ratio has poor "Q" since it begins to support other modes
such as radial and circumferential to the detriment of the longitudinal that
you are trying to use - ie larger diameter is not always better.
That is my nickel on tuned pipes - for whatever it is worth (we get exposed
to a bit of this sort of thing when trying to suppress destructive acoustic
instabilities in rocket combustion) - Vance

 
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