The Rotory Engin is Basically has "2 triangle's" AKA Rotors. They dont move up and down like pistons, then Rotate in side the Chamber. There is 1 chamber for each rotor, and 2 spark plugs for each chmber, Rotory Engins dont have Valves in them they have "Ports" like Intake Port and Exhaust Port. They are Very Powerfull Motors but useually after 140K they need a Rebuild, cus the Apex Seals wear out on them, The Apex Seals are like Piston Rings on a piston. Thats pretty much what a Rotory is, its not a Full summery, i could go on for a long time, but what i said is pretty much the Basic Knowlege that most people know of the Rotry. Yea i can be wrong about RX-7's not beign Twin Turbo, but i have never seen any "Twin Turbo's"Come that are Stock 2nd gens they are all Single Turbo. You might be Confused when you Look at a 2nd Gen Rx-7 they have a "13B Intercooled Turbo II" Around the Intercooler Plate. That is just Stating that its a Turbo Charged, a Twin Turbo would have Duel Air Boxes too, and the Ones that say Turbo II arent twin turbo.