Vance W Jaqua wrote:

There was some mention of a 2 stroke Wankel, and that got the brain cells
agitiated. I had often said tha a two stroke w\Wankel would be very
difficult, so I tried. Converting any positive displacement 4 stroke engine
to an externally scavanged 2 stroke is very attractive. At the same BMEP
and peak loads, you have the potential for twice the torque (and of course
BHP) at the same rpm. Of course there is always a downside - ie the
integrated heat load is also doubled, and you need some sort of external
pump..
To convert (or really build) a 2 stroke classicc trochoid Wankel. you
need to use side porting that opens an exhaust port before rotor BDC
(max chamber volume), and shortly theafter open the intake port
to push the residual gases out and charge the volume, It is useful
to close the exhaust port to complete the charging (and perhaps some
super charging). The rather artsy geometric figure attached represents
the rotor surface excursion in 10 degree incrementsof rotor rotation.
The shaded areas represent the port areas as defined by the rotor edge
(seal location modifies ths some what). Rotor rotation is clockwise
and the 2 sparkplugs would fire six times (power strokes) per
rotor revolution. Port areas seem rather restrictive and can only
be increased with more ovelap or duration.
An interesting exercise, and I would be intersted in the system
planned by the person that saked for the trochiod equations.
Vance J

Vance concept first. Hans second.

Paul Lamar
 
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