Porsche has just filed a patent for a strange thermal engine that operates on a six-stroke cycle instead of the usual four.
Porsche is reportedly working on a six-stroke electric engine. If you’re not familiar with the basics of an internal combustion engine, you should know that, with a few exceptions, All cars with a combustion engine use a four-stroke engine.The four strokes in question are: 1: air and fuel intake; 2: compression; 3: expansion; 4: exhaust.
During intake, an air-fuel mixture is drawn into the cylinder and then compressed by the piston. A spark causes the mixture to explode, which pushes the piston down and produces the power needed to operate the engine. Finally, the burnt gases are evacuated during the exhaust phase.
Two more steps, but for what purpose?
So far, nothing new under the sun, but Porsche engineers are reportedly studying a new type of engine with a different compression phase. Documents filed with the United States Patent and Trademark Office (No. 18/585,308 filed last February for those interested) specifically describe this as “six individual phases which can be divided into two sequences of three phases”. The two additional steps would occur between the compression phase and the exhaust phase. The first sequence would therefore be intake-compression-expansion, followed by compression-expansion-exhaust.
To try to schematize this system, the patent of Porsche shows a crankshaft rotating on a ring with two concentric circles. This changes the center point of rotation, which slightly lowers the piston stroke. This also causes a change in compression, since the piston goes less high in the cylinder during expansion. More simply, This means that this engine has sort of two dead centers, top and bottom..
A project without a future
On paper, it sounds complex, and in practice it seems to be just as complex. Although Porsche is not yet providing details on this, this design has the potential to generate more power with better efficiency. In a conventional engine, only one stroke out of four actually produces power.
With this “formula”, it allows to go to one time in three while having a better combustion. To see if the gains will be sufficient to justify a design that seems at the very least complex, while knowing that it will probably take a few years before arriving at making the whole thing reliable.
However, as is the case with many patents, It is possible that this project will never see the light of day..
The fact remains that Porsche does not yet seem to have completely abandoned the idea of offering thermal engines to its customers.
Source: www.autoplus.fr
