Not every motorist knows that there are not only classic piston engines, but also rotary engines. This is due to the extreme rarity of the latter. The only manufacturer in the world, mass-producing cars with a rotary engine - Mazda. Let's take a closer look at the key features of this motor.
As an example, take the most popular rotary engine "Mazda RX8" - 13B MSP.
General information
Motor 13B MSP has the generally accepted and well-known name Renesis, which will appear in this article. I would like to note that he received the title "Engine of the Year" back in 2003. We will not go too deep into the history of the invention, we will only say that the principle of the operation of such a motor was invented by Felix Wankel and Walter Freude in 1954, although the first developments began back in the 30s.
In 1958, NSU launched the world's first car with a rotary piston engine (in the distant RPD). And after a few years, the Mazda company began to manufacture RPDs at its own facilities. Therefore, at present, only this company has vast experience in the use of rotary piston engines in automobiles.
Briefly about the principle of the RPD and the benefits
The design of the motor has a stator, which is an analog of the cylinder block in the classic ICE, as well as a rotor, which is, in fact, a piston. The eccentric shaft acts as a crankshaft. Actually, a mechanism such as apex is used, which is used to isolate internal combustion chambers. This is one of the most heavily loaded parts in terms of temperature difference.
Such a motor has a number of advantages. The Mazda RX8 rotary engine , which will be reviewed in this article, is extremely compact. It has much less parts than a conventional piston. This, without a doubt, increases its reliability. The return in this case is also much higher. A volume of 1.3 liters is enough to achieve a power of 250 horsepower.
Disadvantages of Renesis
As you might have guessed, motors of this type are not widely used. And there are a number of good reasons for this. Firstly, low engine life. The design is made in such a way that after a certain mileage, the assembly fails. Of course, the classic piston engine also fulfills its own, but this is a completely different story.
How long the RPD will work depends on the driving style, but in most cases the mileage stops at around 100,000 km. Of course, there have been cases when the motor ran 200,000 km, but this is more likely an exception to the rule than a regular situation. The RPD itself is considered a consumable, so most often it is simply replaced with a new one.
Not for a quiet ride
The Mazda RX8 rotary engine, the technical characteristics of which are discussed in the review, is often purchased for high speeds and a feeling of constant drive. Work at high speeds, although it does less harm than a piston engine, but still significantly reduces the resource. Typically, the mark drops to 80,000 km, and in some cases to 50,000 km. Then comes either overhaul and bulkhead, or the installation of a new motor.
There is another important nuance - the RPD does not tolerate overheating, although it is prone to them. That is why you need to carefully monitor the health of the cooling system on the car. Replace antifreeze, thermostat and other consumables in time. Since the minimum savings can result in maximum costs.
More moody
Since the Mazda RX8 rotary engine often operates in extreme conditions, it must be carefully maintained. In particular, this concerns the regularity of oil changes. It is advisable to perform this procedure every 5,000 km. Given that the oil change in this engine is partial, this should not be a problem. Tightening is highly discouraged, since you can “get” to the new engine, even overhaul will not help.
As noted a little above, the apex is one of the most loaded elements of the system. This plate is a seal between the combustion chambers. Therefore, it is constantly under load from temperature and pressure differences. Partially, the designers managed to solve the problem with its wear using high alloy steel. Nevertheless, the apex usually fails first.
Search for service stations is a science
Even today, not every car service center will undertake to repair such an engine. In Russia, maybe a dozen such service stations are gathered, which are located mainly in large cities, such as Moscow or St. Petersburg. But what to do to the owners of such a car in the province is completely incomprehensible. This is one of the key factors that prevent people from buying cars with a similar engine.
But even if there is a service with such specialists, then where to get spare parts? They will have to be ordered and, most likely, it will take a long time to wait. Of course, the Mazda RX8 rotary engine, whose resource is already small, may decrease due to unskilled service employees. Therefore, I don’t want to give away a car somewhere either. Most likely, the declared amount for repair of the RPD will be just amazing, but it already depends on the audacity of a particular minder.
Renesis Engine Enhancement
The company "Mazda" after the release of the RX-7 took into account some of the shortcomings of the motor and tried to improve it. After a series of manipulations, most of which were not disclosed, the developer said that, depending on the driving style, the engine will work from 300,000 to 450,000 kilometers. True, he forgot to add that for this period there are also 3-4 overhauls. This is precisely the situation today.
The only significant upgrade that has benefited is the installation of two oil nozzles. Although here it was not without flaws. Their design was not the most successful, so the apexes were not lubricated enough and sintered very quickly. This minus has been eliminated in restyling. Well, now it will be useful to talk about the features of the operation of this motor.
What is the engine afraid of?
We have already figured out a little with you what makes the Mazda RX8 rotary engine interesting. The operating principle, advantages and disadvantages are also considered. And now about other important details. RPD is extremely afraid:
- oil starvation;
- overheating;
- bad fuel;
- long drive at high speeds.
As for the first two points, then everything is extremely clear. Bad gasoline really affects RPD performance. Possible detonation and unstable activity. Therefore, it is highly recommended that you fill in the best fuel that can only be found at the gas station. As for high revs, they cause overheating. Although sometimes it is necessary to give gas to remove carbon deposits and blow out candles, but this should be short-lived.
About maintenance costs
And this is perhaps the most interesting. Despite the relatively low cost of the car, you will have to invest in it specifically in any case. The first and most important thing is fuel consumption. Here it is quite impressive. On the highway about 10-12 liters, and in the city from 13 to 20. But this is in the case of proper operation of all systems and nodes. If there is at least a faulty lambda probe, the flow is averaged and rises to 20 liters or more.
Keep in mind that the car is extremely reluctant to consume AI-92, so you will have to feed the 95th. Consequently, expenses also increase somewhat. But that is far from all. Oil car also eagerly eats. The flow rate is about 500-1000 ml per 1,000 km, depending on how you press on the accelerator. An original liter bottle costs about 1,000 rubles. But you can find a quality substitute for 500 rubles per liter. Keeping such a workhorse is extremely difficult. The car is more suitable for ceremonial trips than daily pushing through traffic jams from work to work.
Mazda RX8 rotary engine: reviews from owners and experts
According to most experts, there is one huge plus of such a motor. It consists in its low weight. The same "Renesis" has a mass of not much more than one hundred kilograms. If you take a motor of similar power, then this is all 250-300 kg. In general, such a power unit on the RX8 allowed to significantly improve the balancing of the car and reduce weight.
Another key advantage, according to many - high efficiency and the absence of vibrations per se. This makes the ride more comfortable at high speeds, since the engine is not too noisy, and it has a fairly pleasant sound. But experts of many service stations note that this is an extremely whimsical motor and, in fact, unpredictable. He can walk as long as the manufacturer has set a time limit, and many times less. This does not give any confidence in the future.
One more minus - the resource of work is reduced at low temperatures. This, of course, applies to conventional cylinder-piston engines, but RPD has succeeded here. Mazda has developed a special system for the cold start of the Sub-Zero Start, which partially solved this problem.
Is there a Renesis tuning
Many car owners would like to modify the Mazda RX8 rotary engine. Reviews also indicate the inappropriateness of tuning. This is primarily due to its high cost and complexity. The RPD resource also influences, which is already quite low, and hardly anyone wants to reduce it even more.
That is why they often try to install a different engine on this car rather than tuning this one. True, in most cases, such attempts do not lead to anything. RPD has a small mass, in this case 110 kg. The only more or less sane option is to install the RX-7 RPD, which is considered more tenacious. Although 90% of the owners ride on what they put at the plant, that is, in stock, and are very satisfied.
To summarize
Much has been said about the Mazda RX8 rotary engine. You can look at the photo of the RPD in this article and see its key differences from the classic piston engine. From the foregoing, we can conclude that the motor is extremely picky. It does not tolerate low temperatures, requires regular care and maintenance. Also very "gluttonous", this applies to both oil and gasoline.
But he has his own strengths. It gives excellent dynamics, a large number of horsepower from a small volume, a pleasant sound and indescribable sensations. Such an engine is more suitable for ardent fans of this car, rather than for people who consider their money.
Costs can really be big. If, for example, you notice that the RPD does not start up hot, or the compression dropped below 6.5 Atm, then this is likely to lead to an early death of the engine. In this case, it is better not to delay the overhaul. In general, the Mazda RX8 rotary engine, the principle of operation of which was considered in this article, is somewhat unfinished. This applies not only to this RPD model, but to all engines of this type as a whole.
It is hardly necessary to talk about the price of Renesis. This pleasure is not cheap. Add to this the work at the service station - and goes to 100,000-130,000 thousand rubles. For some, this amount is not so big for a new engine, but you should also consider the cost of a car. Gasoline, oil in large quantities, MOT, etc. When everything goes together, the amount will increase to 300,000 rubles or more. After that, it is worth considering whether the Mazda RX8 rotary engine is so good. Although its characteristics are impressive, there are a lot of drawbacks.