The rotary (Wankel) engine trades pistons for precision geometry. Instead of cylinders moving up and down, it uses a triangular rotor spinning inside an epitrochoid housing—a special oval-like chamber that keeps each rotor face performing a different part of the four-stroke cycle at once. Here’s how it works step by step: 1️⃣ Intake: As the rotor spins, one chamber expands, drawing in the air-fuel mix. 2️⃣ Compression: The rotor’s motion then squeezes that mix as the chamber volume shrinks. 3️⃣ Power stroke: When the spark plug fires, combustion pushes the rotor further along its path—this is the only part that produces work. 4️⃣ Exhaust: The gases are expelled as the rotor completes its turn, and the cycle repeats. Because three rotor faces operate simultaneously, the rotary engine delivers continuous power pulses with fewer moving parts. It’s compact, smooth, and capable of very high RPMs. But its design also makes sealing tricky—apex seals wear fast, fuel economy lags, and emissio...