1. They burn out the exhaust system.
2. They wear out after 30,000 km and start to smoke.
3. They use too much fuel.
4. The seals go on them and they start to leak oil.
5. They are unreliable and break down often.
6. They are complicated and hard to repair.
7. They are only suitable for performance use.
8. A Rotary needs to be warmed up before each use.
9. Rotary mechanics are impossible to find.
10. They make too much noise.

Like anything new or revolutionary, the Rotary Engine has received more than it's fair share of bad press generating all sorts of myths and rumour.

The following page will attempt to explain, and in many cases dispel, various myths and rumours that regularly grace our email box in the form of inquiries.

The exhaust system on a rotary engine is often exposed to higher temperatures than with conventional engines. Gasses are still partly ignited as they exit the engine and race down the exhaust as anyone starting an engine with no exhaust fitted can testify.


For this reason, rotaries mostly require heavy duty, thicker walled tubing to last as long as the exhaust on conventional engines. A well prepared rotary will have a suitable exhaust system fitted to it. Look for this when buying one.

A couple of things here. A rotary owner is usually a rev-head and will drive faster, harder, and with less compassion for the equipment than the average Joe. That means that most rotary powered cars are driven harder than usual and as a result, explode with regularity. I suspect that this is why people have come to believe they are short lived engines. Poor reliability in the early days has not helped and although problems have been long solved, the stigma of un-reliability has survived.
It is my belief that if you look after your rotary by keeping it well tuned with clean oil and good cooling and most importantly, don't thrash it all the time, these days it will last as long as any conventional engine under similar treatment.


I have said before that if you treat your car like a race car, you will have many unscheduled pit stops.

How much is too much. If you want to go fast, sound great and basically do the business, there is a price and that includes fuel consumption. Big Weber carbies will use more than a standard set up etc etc.


If you drive around like grandma in a stock-standard rotary without ever going beyond 3 grand, it will almost run on a fart. If you drive around on the limit at 6 to 10 grand in a PP full house racer it will cost you as much for fuel as a big block V8. It is all very relative.

The compression seals in the engine have been known to let go (usually during a burnout or something), but they don't let go often and like the components in a conventional engine, everything wears out eventually and some things can always fail without warning with any type of engine.


As for oil leaks, there is no reason a rotary should develop an oil leak any faster than a conventional engine. If it's built right, it is not going to leak oil if the oil seals are in good condition and installed correctly.


Yes, a Rotary engine does use a little bit of oil as it operates but this is normal and intentional. There should be two oil injector nozzles at the intake supplied by a pump at the lower/front of the timing case. Rotary owners should check the oil level regularly. Rotaries need this small amount of oil injected to lubricated the various sliding surfaces inside the engine. In a conventional engine, with each stroke, the pistons receive a new coating of oil from their visit to the sump (oily) end of the cylinders.


On the other hand, the compression seals in a Rotary engine do not have contact with lubricating oil at any time as they are bound on both sides by compression chambers and would wear both themselves and the housings very rapidly without this injection of oil. It was a design after-thought that ended up working like a treat. A faulty oil injection system will destroy a perfectly good rotary engine in a very short time.

In the early days, as with any new device, the Rotary engine was unreliable.
That was in the fifties and sixties and unfornunately people still try and tell you this today. These days it is simply not true.


New materials, better manufacturing methods and about thirty years of practise and experience means a modern Rotary engine, taken proper care of, should have a life span at the very least equal to a conventional reciprocating engine. 250 000k's is a pretty good dig for any engine but it can be checked over a bit before you buy.


Having said that, when someone comes to me and says,"I'm getting out of Rotaries, I'm sick of mine blowing up on me !". The first thing I ask them is what were you doing at the time. They inevitably answer..."Oh, a burnout at seven and a half" or something equally as stressful like donuts.


What I'm trying to say is take care of any car and it will take care of you, Rotary or otherwise.

With far fewer moving parts than conventional reciprocating engines, particularly modern multi-cam models, a Rotary engine is not only simpler in it's operation but much easier to repair or replace components.


Anyone with a general mechanical knowledge, patience and a good service manual should be able to rebuild or modify a Rotary Engine without any trouble.

Rotary Engines have been used in a wide variety of situations including non-automotive uses like brush-cutters, lawn mowers, power boats and plant equipment.


In automotive applications they are suitable for all types of tasks where power delivery and smooth operation are welcome qualities such as towing and touring.

Partly true but not entirely correct. A Rotary Engine uses many different types of materials in it's construction and each expands at a different rate when heated. This applies particularly to the rotor seals and internal components around the combustion chamber.


This is one reason it is important to idle the engine for a few minutes on a cold start before driving. Then, to extend engine life even further, drive the first part of the journey easily until the operating temperature has reached it's regular level.


After an initial cold start, more warm ups are not usually required unless the engine has had time to fully cool down. Even so, no engine should be raced immediately after starting as oil may not yet be available to all parts of the engine coming under stress.


Warming up a cold engine (of any type) before use gives the oil a chance to spread throughout the engine and lubricate friction and wear points before subjecting these areas to larger loads (like when driving).

You don't like the thought of learning the intracacies of a very different type of engine like your new Rotary and are concerned that regular mechanics don't know about these strange devices.


There is no need to worry as just about every corner of the globe has many dedicated Rotary workshops and technical services and more are arriving all the time. A quick look in your local directories should reveal a range of services aimed at all types of Rotary application.


Normal automotive mechanics should also be able to either make repairs themselves or refer you to the appropriate people. The Rotary has become such an important part of the modern automotive industry that any recognised training for mechanical trades-people now includes a full appraisal of the Rotary engine as part of the regular curiculum.

Some methods employed to increase the power output of Rotary engines do, unfortunately also increase the level of noise produced. Various porting modifications and alternative carburetor set-ups can also have an effect.


For example, a bridge ported engine, with a basic exhaust system, fitted with a dual throat Weber carb' setup can sometimes create more induction noise from the engine bay than what is heard from the exhaust system at the rear when working hard.


Also to benefit from most popular Rotary performance modifications, the engine is usually fitted with a larger, less restrictive exhaust system, again resulting in increased noise, especially when dirving at high revs.