Hi Ed,

Thanks for the kind words.

It just dawned on me that the main problem here in this
equivalency thingy is that we are trying to compare different types
of I.C. combustion cycles.  To wit:  Otto Cycle as opposed to
Wankel Cycle etc.

See,  if we do it on a PER REV basis,  then in the case of the 4
stroke 4 cylinder,  it only ever gets to suck on two jugs!  The other
2 jugs are either exhausting or powering.  Same idea (sort of) as
what happens in the Wankel.

Another way to look at it is considering the POWER STROKES
per rev that outputs on the crankshaft.  Over the years,  I have
almost exclusively explained performance equivalency  on this
basis.  With a 13B,  we get one 654 cc power pulse per rev per
combustion chamber.  A 2 rotor has 2 pulses per rev,  just like a
normal 2600 cc 4 banger.

The only difference of course is that the DURATION of the Wankel
Cycle power pulses is somewhat longer and overlap compared to a
piston engine,  which is why the 2 rotor Wankel is smoother (no
torque reversals),  and also sounds different.

Anyway,  I think we have now beaten this one to death.  As you
rightly say,  it really doesn't matter because the only thing that is
important is the "bang for the buck",  the inherrent reliability,  and
the power to weight ratio.  

I mean,  where else can you get a BRAND NEW 300 + BHP
powerplant that bare long weighs around 130 Kgs for around $15K
AUD or $10,500 USD? (a 3 rotor 20B with 9.7:1 rotors)   What
does a bare long (no manifolds or accessories) IO 540 weigh,  and
how much do they cost?

Same goes for the 2 rotor 13B. $10K AUD for a BRAND NEW
200+ BHP engine that weighs bare long around 95 Kgs.  But I'm
preaching to the converted here,  so I'll get out of your way now ...

Cheers,

Leon