Mazda 13B Rotary: Everything You Need To Know

Mazda has always been a company that’s not afraid to take risks. This same trait in their development history was where the Mazda designers and engineers were at the forefront of new technologies like internal combustion engines or electric cars for decades before they became popularized today.

A perfect example would be how Skyactiv-X engine technology from years ago helped keep diesel on life support by providing an efficient alternative while being more eco-friendly than regular gasoline-fueled ones – all without sacrificing performance.

Rotary engines are back, and Mazda has abandoned its current lineup to focus on hydrogen-based rotaries. It looks like they’re going all out because, after years of hinting at reinvolvement, this time around, there’s no holding them down.

What are Mazda 13B Rotary Engines? 

The Mazda 13B engine is like the longer version of the Mazda 12A Rotary engine. However, they differ in the total displacement since the total displacement of the two chambers is 1308 cc.

The 13B engine is Mazda’s Wankel Rotary. It powered many of their models, including the RX-7 – a legendary Japanese sports car that defined rotary power for generations before them with its signature sound.

The Mazda 13B rotary engine is the most widely produced, and it has been used for over 30 years. The Mazda 12A has no relation to this newer design, instead of being an elongated version that measures 80 mm thick with 654 cc in each chamber (1/2 of one rotor).

For those who are not aware or need a refresher, earlier versions like 12A engines which had thin 90mm rotor thickness, the Mazda 13B increased this amount to create 80 mm blades as well, according to top researchers who study these things closely. 

The 13B was a popular engine in the United States from 1974 through 1978. When it retired from sedans, it resurfaced again in 1985 and 1986 with RX-7 GSL-SE models before being used once more for two years from 1987 to 1989.

During that time, only naturally aspirated or turbocharged options could be purchased at that point due to its close ties to Toyota’s Supra racing program. 

But then disappeared yet again until 1992 where twin turbos made their return. This last appearance of this legendary powerplant would also mark its swan song, though, since 1995, there were no longer any US market cars available equipped as such…

Engine Specifications and Design:

  • Production Run: 1973 – 2003
  • Cylinder Head Material: N/A
  • Cylinder Block Material: Aluminum
  • Configuration: Rotary
  • Bore: N/A
  • Stroke: N/A
  • Valvetrain: N/A
  • Displacement: 1.3 L (1308 cc)
  • Compression Ratio: 9.4 and 8.5 (Turbo engine)
  • Weight: 337 lbs. 
  • Maximum HP: 280 HP at 7,000 RPM
  • Maximum Torque: 231 lb-ft at 3,500 RPM

Mazda 13B Rotary AP

The first 13B engines had carburetor fuel systems and single distributors in their ignition systems, fitting because these cars are also known as AP. Cars using this type of auto have used the “AP” name since 1974-1980.

Applications of Mazda 13B Rotary AP: 

  • 1975 – 1980 Mazda Cosmo AP
  • 1974 – 1977 Mazda REPU (Rotary Engine Pickup)
  • 1974 – 1977 Mazda Parkway
  • 1975 – 1977 Mazda Roadpacer
  • 1973 – 1978 Mazda RX-4 
  • 1975 – 1980 Mazda RX-5


A tuned intake manifold was used in a Wankel engine for the first time with an even more impressive effect when fitted onto 13B-RESI. RESI stands for Rotary Engine Super Injection.

This particular vehicle featured two levels of opening and closing ports on its air filter box where it derived supercharger-like power from Helmholtz resonance, much better than what we’re accustomed to.

Furthermore, the 13B-RESI engine is a tribute to the most powerful naturally aspirated boxer engines in existence. It features a dual-level intake manifold, which created a supercharger-like effect from Helmholtz resonance and improved power by almost 25%.

Applications of Mazda 13B-RESI: 

  • 1984 – 1985 Mazda HB Luce
  • 1984 – 1985 Mazda HB Cosmo
  • 1984 – 1985 Mazda FB RX-7 GSL-SE


The second-generation RX-7 was a technological marvel in the early 1990s. It featured both variable intake and exhaust systems and four injector electronics that we’re able to produce an impressive 146hp at 6500rpm with 138 lb of torque coming out right when you need it.

The sleek exterior design also includes features such as large air scoops on each side modeled after racing cars from Italy’s Lamborghini company. So drivers could experience true agility while driving around town or even long-distance trips thanks to this high-performing sports car’s incredible performance figures.

In 1986, the Mazda 13B was turbocharged and became an instant engine classic. It has its newer sibling’s four-injector fuel injection system, but it doesn’t have that great variable intake manifold.

And in 1979-’80 model year, 6PI designation was made, but instead of new, we’re left with only some similarities from these features lost over 30 years ago when they were first introduced back in 1974.

Applications of 13B DEI engine: 

  • 1986 – 1988 Mazda FC3S S4 RX-7
  • 1989 – 1991 Mazda FC3S S5 RX-7
  • 1986 – 1991 Mazda HC Luce
  • 1986 – 1988 Mazda FC3S S4 Turbo RX-7
  • 1989 – 1991 Mazda FC3S S5 Turbo RX-7 

13B RE

The 13B-RE from the JC Cosmo series was similar to its bigger brother, but it had some key differences. Firstly they both sported larger side ports than other models in their lineup because of how much power these turbos can produce with ease, and secondly, there’s an injector size difference between them.

At the same time, one Turbo receives 350cc PRI + S Injectors (34 cu inches); another only gets 250 cc.


The third-generation RX-7 introduced a completely redesigned 13B engine, the REW. It was supercharged by twin sequential turbochargers and got two big Hitachi HT 12 turbos for more power to pull off great feats of speed on any driving demands.

The engine received the JC Cosmo series large 57 mm diameter turbo that will be used for the second boost stage. It then adds power with another smaller 51 mm sized 10-inch scroll combined injector’s worth at 4500 pm, just before redline.

The 13B-RE is also equipped with an electrical wastegate system if you want to keep things quiet or have other electronics hampering your horsepower figure.

On top of that, the 13B-REW is a high-performance engine built to handle the demands of boost, power, and loads. It features an enhanced cooling system with revised intake valves for better combustion while managing increased temperatures caused by this pressure injection technique or “racing fuel.”

The car makes its driver feel at one with his vehicle as they take corners. There are no turbo lag response times when strapping into these seats – instead of experiencing instant gratification time after every apex.

With a new engine management system, the 13B-REW is more efficient and responsive. The data parameters have been optimized for better monitoring of air/fuel ratio and ignition timing control to ensure that there are no lags or slips in your driving experience.

 With its standard equipment with an Air-To-Air intercooler installed on top, this vehicle will provide high speeds across country roadways without any hiccups along the way.

The engine’s power rating is 255 HP at 6,500 RPM at the beginning of the sales and 217 lb-ft of torque at 5,000 RPM. However, in 1993, the engine became more powerful with its 265 HP, and in 1999, 280 HP.

The 13B REW engine produced lasted until 2003 and eventually departed. 

Applications of Mazda 13B-REW engine: 

  • 1992 – 1995 Mazda RX-7, 255 HP
  • 1996 – 1998 Mazda RX-7, 265 HP
  • 1999 – 2002 Mazda RX-7, 280 HP 

Problems Surrounding Mazda 13B Rotary Engines: 

Engine problems can be hard to deal with because they happen naturally due to factors such as age, mileage, and maintenance habits in the long run. However, no matter how well designed your engine is, issues will still come up caused by different timelines over a time frame.

Mileage may seem like an obvious indicator, but it’s not always accurate; for example, if someone drives their car everywhere, then sometimes that person might drive more than others which could lead them to have higher usage rates on certain parts (i.e., oil changes).

1. Excessive Oil Consumption 

The engine burns oil, and this is how the car was designed to operate. The little injectors inside it shoot out a thin stream used for lubricating parts or just prolonging their life in general by providing extra protection against harsh conditions like heat from flames. I

It’s important, so you know when your vehicle needs some maintenance because if there aren’t any more fluids being shot into these combustion chambers after an extended period.

Something may have worn down over time, resulting in increased wear-and-tear on both components and high repair costs associated with the lack of repairs needed at all.

However, the 1989-91 RX-7 is the perfect match for reducing oil consumption. It’s 25% less than what’s required in 1986 and 1988 models, which was electronically metered system equipped cars with no vacuum pump.

2. Engine Overheating

The second important task for your car’s engine is preventing overheating. The most common causes of this happening are coolant leaks and thermostat failures, which can be prevented with a regular change-o’-the-water service every 12 – 18 months as well as inspection on hoses or belts to prevent problems down the road.


If you are looking for an engine that is practical, fuel-efficient, and great on the environment, then look to other engine options. The 13B should be reserved for those who want performance at all costs.

But if you can afford it and have no environmental concerns, this may be the best choice of engines out there.

The catch is that rotary engines are not practical for a daily driver. The cars with 13B are not the best in fuel economy and require more care. There is a reason those engines are used in the racing primary where durability isn’t the critical factor. 

But the Mazda 13B can be as reliable as a piston engine. It needs regular maintenance and proper oil, and good quality gas.

Leave a Comment