𝙏𝙝𝙚𝙤𝙧𝙚𝙩𝙞𝙘𝙖𝙡 𝙘𝙤𝙣𝙘𝙚𝙥𝙩 𝙤𝙛 𝙢𝙮 𝙣𝙚𝙬 𝙞𝙣𝙫𝙚𝙣𝙩𝙚𝙙 𝙞𝙣𝙩𝙚𝙧𝙣𝙖𝙡 𝙘𝙤𝙢𝙗𝙪𝙨𝙩𝙞𝙤𝙣 𝙚𝙣𝙜𝙞𝙣𝙚 The “duality” engine has no valves, no crankshaft, no flywheel, no timing belt/chain with the appropriate adjustments can run any fuel. Light weight and cheap to manufacture, can be made from mono-block as no valves to deal with. Vibration can be an issue if it is not desired (motorcycle…) but can be dealt with by having a twin running on opposite cycle. Can be configured in line (serial), two or more side by side (parallel) or horizontal boxer. Right triangle configuration of three duality’s (six cylinder) at 120° to each other with either exhaust or intake port in center is another option. Spark can be generated form magneto or capacitor discharge ignition. Electric linear actuator (helenoid, colenoid) can be used to start or cheap and simple mechanical setup like hair-clipper/grass mowers. If interdependently operated it can run in “eco mode” with only two of four/six/eight... cylinders operating with driver going across town in city traffic and the other(s) started up when more power is required. Differential or drive shaft is not needed as air or liquid can be used for propulsion and turn the wheels. Will see if I find a model engine engineer to make a working model. The duality (yin-yang, husband and wife, whatever you like to call it) engine is a dream for every mechanical engineer as lots of configuration, uses, fuel types or sizes are at hand to utilize. If discussed somewhere else try to include source. Please feel free to like (as many times you want) and share this timestamped post. https://bico.media/86cfce1f6a0c144a5cceda57a6c9f12dfced7e5b9278e1ebe31ca7906c7609ed