A 'standard' (pun not intended) engine uses pistons & cylinders to
combust the air-fuel mix and turn it into rotary power. Dismantle
the lawn mower when nobody's looking to get a first hand example of
this. Leave it apart for added effect!
The rotary, or Wankel, engine uses a rotor instead of pistons. The
rotor is shaped like a bulged triangle and moves in an eccentric
motion inside a 'cylinder' somewhat of the shape of a bulged '8'.
Consequently, there are 3 'combustion chambers' per rotor. Each
is sealed off from one another with the equivalent of a piston ring.
The rotor moves from one end of the 8 to the other, while rotating.
Air-fuel mix enters from one side (of the 8-chamber), gets compressed
along the top and is ignited just after the point of most compression.
The explosion pushes the rotor around and the cycle begins again.
Exhaust gases escape from a port just 'before' the intake port.
Each rotor is the equivalent of 3 cylinders. Mazda's rotary in the
RX series car has 2 rotors, therefore has roughly the same performance
as a V-6. I have seen too many proud RX7 owners claiming that they can
do burnouts with a 4-banger, truth is that there's 2 plugs per chamber;
otherwise the piston pattern would be parallel twin... none too efficient.
The net result is far more powerful (and higher revving) than a
conventional piston engine. RPM around 13,000 can be acheived.
However, a 'ring job' on a Wankel is a true nightmare! Because
they aren't rings, so to speak, but metal seals, you must replace
much more metal than a piston ring.
I have not had the chance to fool about with a working rotary engine.
I did get to dismantle a burned-out Madza mill but there were so many
missing pieces it wasn't really worth it. Interesing though, the 'head
bolts' are what hold the _whole_ thing together. There's a whole bunch
of them, and once removed, the 'layers' of the engine fall apart.
I'd like to see someone patch 3 or more rotors together and transplant it
into a larger car... because the rotary's so small, you could hide it
somewhere unexpected... a Stag with ~12 cylinders? Yikes!
I have an auto mechanics textbook from the high school beside me, so I
can probably answer *some* questions.
Hope this sheds some light on the matter...
-Malcolm
Too many rocks and not enough sand.
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