Description

5. Key Features & Benefits

Complete Swap Package

• Genuine JDM Mazda 20B 3-rotor engine
• OEM Eunos Cosmo automatic transmission
• Rear differential included
• Complete rear subframe assembly
• Imported directly from Japan

Legendary 3-Rotor Performance

• Factory triple-rotor configuration
• Exceptional power potential
• Smooth and balanced operation
• Unique rotary sound and character
• Excellent foundation for turbo upgrades

Rare Collector’s Item

• Increasingly difficult to source worldwide
• Highly desirable among rotary enthusiasts
• Genuine Eunos Cosmo drivetrain package
• Original Japanese-market components
• Excellent investment-grade rotary setup

Builder Advantages

• Complete drivetrain package simplifies swaps
• Ideal for custom fabrication projects
• Suitable for street, race, and show vehicles
• Strong aftermarket support
• Highly respected within the rotary community

6. Detailed Product Description

The Legendary Mazda 20B Triple-Rotor Engine

Few engines have achieved the legendary status of the Mazda 20B. Originally developed for the luxury-focused Eunos Cosmo, the 20B represented the pinnacle of Mazda’s rotary engineering program and remains the only production three-rotor engine ever installed in a factory passenger vehicle.

Unlike conventional piston engines, the 20B utilizes three rotors working in harmony to produce exceptionally smooth power delivery and an unmistakable rotary exhaust note. The engine’s unique design allows it to rev freely while maintaining a compact footprint, making it a favorite among performance builders and custom fabrication specialists.

Today, authentic 20B engines have become increasingly rare, making complete packages like this highly desirable within the global rotary community.

Complete Drivetrain Package

One of the biggest advantages of this offering is that it includes much more than just the engine.

This package consists of:

Included Components

• Genuine Mazda 20B 3-Rotor Long Block
• OEM Eunos Cosmo Automatic Transmission
• Rear Differential Assembly
• Complete Rear Subframe Assembly
• Associated Drivetrain Components
• Imported JDM Package

Because the drivetrain components remain together as a complete package, buyers benefit from improved compatibility and simplified planning for engine swaps or restoration projects.

Genuine JDM Eunos Cosmo Origin

This engine package was removed from a Japanese-market Eunos Cosmo, the flagship luxury coupe that showcased Mazda’s most advanced rotary technologies.

The Eunos Cosmo platform remains highly respected for its engineering sophistication and remains the primary source for genuine factory 20B engines. Purchasing a complete package from the original donor platform provides confidence regarding component compatibility and authenticity.

Exceptional Power Potential

The Mazda 20B platform is famous for its ability to produce remarkable horsepower numbers while maintaining excellent drivability.

Even in stock form, the triple-rotor design offers impressive torque delivery and smooth acceleration. For performance enthusiasts, the 20B is often considered one of the best foundations available for building high-output rotary projects.

Common applications include:

• High-performance street cars
• Drag racing vehicles
• Drift cars
• Time attack builds
• Show cars
• Custom fabrication projects
• Professional motorsport applications

With appropriate modifications, many 20B builds have achieved power levels far beyond factory specifications.

Why Enthusiasts Love the 20B

The appeal of the 20B goes beyond horsepower figures.

Enthusiasts are drawn to the engine because of its:

• Unique triple-rotor sound
• Exceptional smoothness
• Rare factory heritage
• Legendary tuning potential
• Strong collector value
• Exclusive status within the rotary community

Owning a genuine 20B engine is often considered a milestone achievement among rotary enthusiasts.

Ideal Foundation for Engine Swaps

The JDM Mazda 20B 3-Rotor Engine with Rear Diff & Subframe – Complete JDM Package is particularly attractive for builders planning custom swaps.

Popular applications include:

• Mazda RX-7 FD3S conversions
• Mazda RX-7 FC3S projects
• Mazda RX-8 swaps
• Custom tube-frame race cars
• Restomod builds
• Vintage Mazda projects
• One-off performance vehicles

Because the drivetrain package includes the rear differential and subframe assembly, builders gain access to additional OEM components that may simplify fabrication and drivetrain integration.

Engine Specifications

Package Contents

• Genuine Mazda 20B 3-rotor engine
• OEM Eunos Cosmo automatic transmission
• Rear differential assembly
• Complete rear subframe assembly
• Imported from Japan

Engine Configuration

• Triple-rotor rotary engine
• Factory Mazda 20B platform
• Original JDM specification
• Suitable for naturally aspirated or turbocharged projects

Condition

• Good used condition
• Imported directly from Japan
• Sold as a complete package
• Not being separated into individual components

7. Why Choose This Product?

Finding a complete, authentic 20B drivetrain package has become increasingly difficult as demand continues to rise among enthusiasts worldwide.

This package stands out because it includes the major drivetrain components together, providing significant value and convenience compared to sourcing parts individually.

Benefits include:

• Genuine factory 20B engine
• Complete drivetrain package
• Rare JDM import
• Excellent swap candidate
• Collector-grade rotary component
• Proven Eunos Cosmo platform
• Strong long-term desirability
• Ideal for serious rotary projects

Whether you’re building a dream RX-7, restoring a rare Mazda platform, or collecting iconic Japanese performance components, this package offers a unique opportunity to secure one of Mazda’s most legendary engines.

8. Perfect For

• Mazda RX-7 FD3S swaps
• Mazda RX-7 FC3S builds
• RX-8 conversion projects
• Rotary engine collectors
• Performance car builders
• Drift car projects
• Drag racing applications
• Restomod enthusiasts
• JDM collectors
• Custom fabrication shops
• Motorsport projects

9. Frequently Asked Questions

What engine is included in this package?

The package includes a genuine Mazda 20B triple-rotor engine removed from a Japanese-market Eunos Cosmo.

Does the package include a transmission?

Yes. The OEM Eunos Cosmo automatic transmission is included.

Is the rear differential included?

Yes. The rear differential assembly is included as part of the complete drivetrain package.

Does the package include the rear subframe?

Yes. The complete rear subframe assembly is included.

Can the 20B be installed into an RX-7?

Yes. The 20B is a popular swap choice for FD3S and FC3S RX-7 builds, though custom fabrication and supporting modifications may be required.

Is this engine suitable for turbo upgrades?

Absolutely. The 20B platform is highly respected for its turbocharging potential and has become a favorite among high-horsepower rotary builders.

Will components be sold separately?

No. This package is being sold as a complete drivetrain package and is not being parted out.

Is international shipping available?

Please contact us directly for current shipping options, availability, and freight quotes.

Opportunities to purchase a genuine JDM Mazda 20B 3-Rotor Engine with Rear Diff & Subframe – Complete JDM Package are becoming increasingly rare. Whether you’re planning a world-class rotary swap, building a high-horsepower performance vehicle, or adding a legendary Mazda drivetrain to your collection, this package delivers exceptional value and authenticity.

Contact us today for availability, shipping information, additional photos, and purchasing details before this rare 20B package is gone.

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