My only interjection on the Wankel displacement controversy; 1 chamber
is the basic calculation, but if compared to a piston 4 cycle you need
to compare to the same number of crank revolutions. We still measure the
HP using the same formula and measure torque the same way. We still
measure RPM's. Not pulses or fillings or whatever. To compare a Wankel
to a piston I have to go with the 2x a chamber that Paul has been using.

My logic is simple 1 face is always in an "overlap" phase and is
"inactive." That is just my term for it. BTW Adam the 500cc Honda V4 2
stroke crankcase reed valve engine idled fine, and it made 200HP! The
power output of most 2 cycles was limited mostly by the bore/stroke
ratio. Even the highest output engines were usually very close to square
bore=stroke. The balance was between the available port area,
compression which varies with exhaust port height, and crankcase volume.
Less is better usually to help the lower pump feed the cylinder.

The GP
racing 2 cycles were mostly limited to about 10K rpm as a max. They
could rev higher easily but would be beyond max power. Until the
metallurgy and engine management systems allowed surreal RPMs 18-19k
improving BMEP most of the 2 cycles DID produce nearly 2X the equivalent
4 cycle power.

Smog killed 2 cycles, nothing else and sadly modern
direct injection systems would probably allow them to pass today, but
nobody tries due to flat bans most places. The Wankel being able to
achieve intake efficiency beyond 1 using tuned intakes/exhaust really
improves power vs. displacement. It compares well with a 2 cycle.

The
Wankel rotary is so different that comparisons are always hard. Every
time you compare a rotary to a piston engine anywhere near the same
power the piston engine comes up a loser, which is probably what lead to
the displacement controversy in the first place!
Bill Jepson



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