Mazda 12A Rotary Engine Specs, Problems & Reliability


Mazda 12A Rotary Engine

Here in this post, I have gathered information about the Mazda 12A Rotary Engine from its official website, including its specifications, Problems, and Reliability.

We believe in providing reliable information to our readers, therefore we prefer to obtain information on the Mazda 12A Rotary Engine from authentic sources.


This article, which has been updated, has all the information you require about the Mazda 12A Rotary Engine.

Mazda 12A Rotary Engine

The 12A engine was made by Mazda from 1970 to 1985. It had a Wankel rotary design. The 12A has a smaller engine than the 10A (the first rotary engine in mass production).

Both rotors in the engine rotated at the same speed, and the engine was of a two-rotor design.


By increasing the depth from 50 mm (0.39 in) to 70 mm (2.8 in), we were able to raise the chamber size to 573 cc and the overall displacement to 1146 cc (573×2).

Manufacturer Mazda
Oil Change Interval 7,500 miles
Engine Code 12A
Cylinder Block Material Aluminium
Fuel System Carbureted (turbo variant got electronic fuel injection)
Production Years 1970-1985
Configuration Dual-rotor, Wankle (rotary engine)
Displacement 1146 cc
Compression Ratio 9.4:1 (turbo variant — 8.5:1)
Engine Oil Capacity 4.2 litres
Torque 100-115 lb-ft @3500 rpm
Power : 100-130 hp @7000 rpm
Engine Weight  384 lbs (dry)
Engine Oil Weight .

Mazda 12A Rotary Engine Problems

Clogged Ports and Worn-out Quick Apex Seals

The optimum usage of oil is especially crucial for the efficiency of rotary engines.

If you don’t have enough flowing via these pipes into each section, it could get damaged over time due to intense wear and tear from friction against surfaces moving in all directions with each turn, which can be seen by looking at this small device up above to determine if you have enough.

Burning engine oil is not recommended since it leaves a residue. This leads to blocked pores; using 2-stroke oil, which is specially formulated with high-quality lubricants to burn cleanly without producing soot or other harmful byproducts, allows for a fast apex seal to alert you to any problems.


A simple way to fix this problem is to turn off the overall motor power (OMP) and send pure gasoline through your car’s system as a premix. 

Overheated Engine

The 12A engine, while operating without turbochargers, has a far higher rate of reliability.

Maintaining your truck regularly can help it last for up to 150,000 miles without breaking down or developing costly problems like coolant or oil leaks.

The engine produces heat, and if you don’t shut it off, you risk losing precious coolant and, ultimately, possibly having to dismantle everything and start over.

You should also know that rotary engines are the most inefficient and hence use the most gasoline.

Mazda 12A Rotary Engine Reliability

With rotary implants, preventative care is crucial. There is a laundry list of other rotary-specific maintenance rituals you should be completed on a regular basis as well, like checking the oil level.

True enthusiasts and purists will appreciate this platform precisely because it caters to their needs.

Oil consumption is high in rotary engines because of the oil metering pump (OMP).

Its function is to pump oil from the lubricating system and deliver it, via specialized oil injectors, to the apex seals.

Letting it run low on oil is the worst thing you can do to it.

Because the 12A will produce a great deal of soot and debris if it is burning oil, which will accelerate the wear on the apex seals.

If you replace the stock OMP with 2-stroke oil in your gas tank as a premix, you should no longer experience this problem.

If your 12A has bridge ports or peripheral ports, you should do this immediately.

The naturally aspirated 12A engine is substantially more dependable than the turbo version.

With any luck and regular care, your NA 12A engine shouldn’t need to be rebuilt until about 150,000 miles.

Mazda 12A Rotary Engine Review 

Mazda 12A was a four-rotor 1.1-liter engine produced between 1970 and 1985. The Mazda 12A rotary engine was the first mass-produced rotary motor. It was used on a variety of Mazda vehicles including the RX-2 RX-3 and RX-4. For a full review, please check this YouTube video Here.

Mazda 12A Rotary Engine FAQ

Is the 12A rotary engine reliable?

It’s worth noting that naturally aspirated 12A engines are much more reliable than their turbo counterparts.

With regular servicing, the N/A 12A motor should not require replacement before 150,000 kilometres. The engine consumes a lot of fuel, so plan accordingly.

How many liters is a 12A rotary?

The “12A” 1.2-liter rotary engine of the FB RX-7 only made 100 hp, but its small size allowed it to be installed low and behind the front axle, resulting in a better centre of gravity and weight distribution than that of a traditional reciprocating engine.

Is a 12A a good engine?

Compared to turbocharged models, normally aspirated 12A engines tend to be more dependable. Your NA 12A may not require a rebuild until after 150,000 miles if you are diligent about performing the prescribed maintenance.

Is a rotary engine reliable?

Even though rotary engines don’t have a good reputation for being reliable, most problems are easy to fix.

What is a 12A engine?

The electronic fuel injection 12A engine found in the Japan-market HB series Cosmo, Luce, and SA series RX-7 was the pinnacle of the line.

In 1982, a 12A turbocharged Cosmo coupe set the record for the fastest Japanese production vehicle. “Semi-direct injection” meant fuel was injected into both rotors simultaneously.


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