After the increase of customs duties in 2011, fans of the powerful rear wheel drive cars more difficult: the old fleet wears out, and bring in RB something with great motor obscenely expensive. Nevertheless, Belarusians still available Used Mazda RX-8 rotary-piston engine capacity of 1, 3 liters and power from 192 to 231 hp
Needless to communicate with this motor?
25 photos and a few videos.
At our feet lies a compact rotary engine Mazda RX-8. Less than an hour later, he will be completely demolished, while experts will tell about all the nuances of its operation and maintenance. But before that - a short educational program on the Wankel engine.
German inventor Felix Wankel in the 20-ies. XX century sought to simplify the design of the engine, saving him from a large number of parts. He succeeded - RAP no crank mechanism, pistons, valves and a complex system of drive. The role carries the stator cylinder shaped epitrochoid (like bloated in the middle of the figure 8). The piston acts as a triangular rotor. Vertices it slides over the surface of the stator, forming three closed cavities. In each of the three cavities in one revolution takes 4 cycles: intake, compression, stroke and production - as usual. The rotor moves along a complex trajectory, which provide two gears. One of them, the inner, is fixedly mounted on a rotor and "trial run" fixed gear fixed to a side wall of the stator. The rotor itself rotates on an eccentric shaft. Since the shaft is removed and the engine torque.
Ideally, everything looks great: a minimum of parts, maximum simplicity and efficiency. In size rotary motor is substantially less piston engines and takes up so much space. This RAP is able to withstand high speed, vibronagruzhennost less. Because of the smaller number of parts of the engine has a low inertia, so in response to the gas spins instantly!
But, as is often the case, the disadvantages of the rotary engine stems from his own merits. Non-ideal shape of the combustion chamber - the cause of inefficiency and high content of harmful substances in exhaust gases. Fuel consumption is higher than that of classic motors. Moreover, a large area of the combustion chamber leads to a greater heat load of the motor. The main enemy of any rotary engine is wear APEX - seal between the combustion chamber. This very small plate has to take on the huge changes in temperature and pressure with a small contact area with the surface of the combustion chamber. To ensure proper lubrication of seals, the intake manifold is necessary to inject further oil. This increased oil consumption and deterioration of environmental parameters. Etc., etc., etc. - about the shortcomings of this motor can talk for hours. The design at first glance seems to be simple, but there are countless nuances.
Many automakers once abandoned development of the RAP, although a patent for the engine purchased: Daimler-Benz, General Motors, Alfa Romeo, Nissan, Toyota. Seriously rotors while engaged in the WHA. And then there was a car as NSU Ro 80, 1967 produces several years of rotary engine of 995 cc capacity of 113 hp But in the end only Mazda has continued to work on improving the design of the Wankel, achieving very good results. And today we are at the station, specializing in repair of engines Mazda RX-7 and RX-8. 04
Before us is the motor 13B. Its power - 192 horsepower, mileage - about 180,000 km. Overhaul was carried out on 120.000 km. The owner of the car came with complaints of a bad start of the hot engine and high consumption of oil consumption. It's time to talk about the resource and the cost of repairs.
- In the United States, Japan and European countries, these motors pass without interference about 200 thousand kilometers - says Vyacheslav master specialized service stations. - But we have a resource engine is on average 100 thousand. It happens less often because they do not receive proper care and high-quality fuel. The first sign of the upcoming overhaul is increased oil consumption, bad run "on hot" and a low level of compression. Before buying such a car be sure to use a special Compression - Compression should not be lower than 6, 5 atmospheres. The cost of the work on the bulkhead of the engine - about $ 1,000, Kit - about 1500. This is assuming that none of the sections, no major items affected. If within a large wear, scuffing or damage, it is recommended to replace the section, which costs about $ 700. If you take care of the engine, to do everything in a timely manner, the engine can drive and 150 thousand. All very predictable: rather through one oil change to measure compression - it should be 6, 5-8 atmospheres. Falls gradually, but below 6-6, 5 atmospheres better not to bring, or a repair kit will not be enough.
There are times when the cost of repairs may be inappropriate. According to Vyacheslav, in this case, can be ordered from the American engine, which are overhauled in the factory, with all the main parts in it are replaced by new ones. From the new engine so you can not tell the difference. Its price - about $ 4,500. From Japan, you can order a new one for about $ 6000-6500. You can view and option b / y.
- The resource is highly dependent on how often change "consumables" and what they are quality. For our clients, we recommend to change the oil every 5000 kilometers. Different markets have different intervals: in Europe, for example, they are 20 thousand. The air filter should be sure to change the time in 20 thousand kilometers. The tank fill only 95th gasoline, but the best of the 98th, although it is, of course, expensive. After all, the RX-8 fuel consumption merciless: in 15 liters or even more. While I believe that the flow rate is quite adequate to power the engine.
Getting dismantling. Master draws attention to the oil injector. The RPD is no direct contact with the pallet sections, so there is oil forced into the sections on the intake stroke.
- If they do not change in time, it can end badly. Note: The oil consumption of the rotary engine should be. What? Original oil canister can hold 5 liters, pour 3, 5 - half liters is enough for 5 thousand kilometers. That is, if all properly. If there are nuances, the flow rate may be higher. If the flow is less, it should cause concern - there is a problem with the nozzles. According to the statistics, they nursed almost 50 thousand kilometers.
The Mazda RX-8 mounted oil cooler, depending on the version there may be two or one. To our eyes the oil thermostat. Oil does not immediately get to the radiators, but only at a certain temperature.
According to Vyacheslav like any motor rotor 13B fears of overheating, but it does not happen often - a common cooling system has a capacity of 9, 5 liters, a rather big heat sink.
Turn off the tray - gaze presents a tricky system protivootlivov. On the RX-8 can safely participate in amateur track days.
Oil pump, according to Vyacheslav, very productive, there are two pressure reducing valve pressure relief oil.
Remove the oil pump cover. Vyacheslav says that the only chain (oil pump) the engine is practically eternal problems with it never had.
Deepen. The engine is attached by bolts 19, which are clamped in a specific sequence. Each bolt has a gland to prevent leakage of coolant. Turn off them.
And here is the rotor. This video reel Vyacheslav clearly tells about the principles of the RAP.
The expert notes that the role of compression rings are performed apexes.
- The problem of small resource lies in the fact that the seal should be provided on three planes. And it is difficult, therefore, initially compression RAP lower, hence a lot of problems. In the old RX-7, all the better. The turbocharged rotary motor vehicle that passes over 200,000, provided the competent service. At Mazda RX-8 is the apex height of 5 mm 3, 4, 5 mm replacement is recommended, therefore, to "life" is withdrawn 0, 8 mm. At RX-7 is the apex height 8, 1 millimeter, it can be erased for 1, 6 millimeters. Therefore resource artificially underestimated, I think - to get into the environmental framework and to increase the engine revving.
- A set of four special candles costs $ 100. Normal can not be used - you can immediately destroy the motor. They need to be changed every 30-40 thousand kilometers. The main thing is not to confuse the marking - various candles.
After less than an hour of work in a calm pace the engine was completely dismantled. Checking the status of components in two sections demonstrated that the shifted first insert of the rotor. In both sections, signs of increased oil consumption - exhaust ports half-coked. Internal wall sections have burrs.
Vyacheslav claims that engine overhaul impractical:
- Total motor wear is high, pulled off the insert rotor major components need to be replaced. If restored, the kind of money you can buy two second hand motor or a "rebildins." Here it is necessary to change the shaft, bearings, gaskets, apex section. That is the price of high-quality recovery of such motor - about $ 4,000. But it's not scary. Sometimes the apex falls and causes serious damage to other parts. By the way, the motor can go to the factory and one section. In this regard, of course, the engine suffers terrible abuse.
Does it make sense?
Vyacheslav, apart from the fact that repairing these machines, he goes to them. What does he think about them? Should I buy?
- I have family there and Mazda RX-7 and RX-8. In fact, these cars are very much good. The ride is pleasant: the motor flexible, easy to spin up to 9000 rpm, depending on the modification. Manageability gorgeous, the design is very interesting. We just need time to change, "consumables" monitor the condition of the nozzles and compression. Besides the engine, everything is extremely reliable - with the electrician and the chassis of nuances in the car there. The choice is available - in the country there are more Mazda RX-8. You can safely buy. But it is worth remembering that such machines are expensive to maintain, at all the money they did not buy, but just not as expensive to buy: for 15.000-16.000 dollars you can pick up a good copy. If everything works, rotary Mazda - continuous positive.