Quote:
Originally Posted by Old Mechanic
Felix Wankel Patented the "Rotary" engine, which is not really a rotary, in 1926, if my memory serves me properly, almost 90 years ago.
The basic flaws are the surface area of the combustion chambers and the problems with sealing the combustion chambers. I had one of the first RX2s and the fuel mileage was atrocious (13.5 MPG). The engine basically blew up at 13k miles and I got a replacement free, even though the car was salvaged.
The surface area and shape of the cumbustion chamber with flat surfaces on the sides means serious heat transfer issues and differential rates of expansion of those surfaces make sealing almost insurmountable, even after 90 years.
To keep the tip seals from melting you have to lubricate the tip seals with oil losses similar to a two stroke engine. Not quite that bad but bad enough that, in my opinion, it's dead end technology.
Many major manufacturers including Mercedes tried to overcome those design "defects" and not one of them has succeeded.
regards
mech
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But, that was 30 years ago. Science and engineering does not stand still.
The sealing is much easier to deal with in this design than on the Wankel/Mazda rotaries. There, the seal was in a dynamic position on the fast moving lobe tips. Cooling was limited. Here, the seals are in a static position and can be provided with cooling more readily.
Heat losses due to surface area can be minimized by coatings. Many coatings are now available to us for just this purpose. In the last 10 years alone, the advances have been notable to reduce heat losses, friction losses and all at a price range that a well equipped garage inventor can use.
The base construction materials themselves are improving not just with coatings and alloys, but in combinations and with fabrication techniques that were not even possible 30 years ago.
Does this mean, this design is going to be successful? No. But, it is less of an issue than you think. The company seems reasonable in making their first markets the small, less restricted engine applications. Once they get their technology in production, incremental improvements may make this engine design more suitable for general transport applications.