Mazda 20B 3-Rotor Engine For Sale

Description

Mazda 20B 3-Rotor Engine
Legendary Rotary Power & Japanese Precision

Mazda 20B 3-Rotor Engine rotary engineering with the Mazda 20B-REW 3-Rotor Twin-Turbo Engine, an iconic masterpiece that powered the luxurious Eunos Cosmo (JC). As the world’s first production 3-rotor engine and the only rotary to feature sequential twin turbocharging, the 20B remains one of the most advanced and revered engines ever produced by Mazda. With its exceptional smoothness, compact size, and exhilarating power output, the 20B engine delivers a truly unforgettable driving experience.

The 20B-REW features three rotors with a total displacement of 1,962 cc, producing up to 280 horsepower (206 kW) at 6,500 rpm and 403 Nm (298 lb-ft) of torque at 3,000 rpm in factory configuration. Thanks to its sequential twin-turbo system, the 20B delivers immediate throttle response and immense high-end performance, offering the seamless rush of power that rotary engines are famous for. The lightweight aluminum rotor housings, liquid-cooled design, and advanced electronic fuel injection contribute to the engine’s smoothness, efficiency, and high-revving capability.

Built for refinement as much as performance, the 20B engine represents Mazda’s engineering artistry — combining rotary smoothness with turbocharged power for an unparalleled experience. The compression ratio of 9.0:1 provides a balance between responsiveness and durability, moreover while the 8-bit ECU-controlled ignition and fuel systems ensure precise combustion and excellent throttle control. Its compact 3-rotor configuration also makes it a popular choice for high-performance swaps, especially in RX-7 and custom builds.

Common Weaknesses & Maintenance Notes

While the Mazda 20B 3-Rotor Eunos Cosmo Engine is robust, it requires dedicated maintenance due to its rotary design. Common issues include apex seal wear, which can cause compression loss if oil levels are neglected. Regular oil top-ups and using high-quality synthetic or semi-synthetic rotary oil are essential to protect the seals and rotors. The twin-turbo system can also develop boost leaks over time; inspecting vacuum hoses and intercooler connections helps maintain peak performance. Additionally, proper cooling system care, flushing and refilling with quality coolant  furthermore prevents overheating and housing warping.

With correct care, the Mazda 20B-REW can deliver years of reliable, high-revving performance, making it one of the most collectible and powerful rotary engines ever built. Each engine we supply is inspected, compression-tested, and imported directly to our warehouse, guaranteeing high quality and long-term reliability.