New 5-Stroke Engine to Boost Efficiency and Reduce Emissions

Our four stroke engines have been around for a very long time and while many small changes have been made to them over those many years, the basic principal of operation has remained the same. Now, a new engine design that uses an additional stroke may be taking over the number 1 position when it comes to small powerplants.

Ilmor Engineering is the firm behind the new design and is currently able to get 130 horsepower and 122lb.ft out of the little engine. Considering the total displacement is 700cc, those numbers are fairly impressive. By using a turbocharger and keeping rotating mass at a minimum, the new engine is said to already be at least 5% more efficient that it's four stroke counterparts.

The team is currently working improving the valvetrain design and testing other turbochargers to see if they can improve on the design even more. They also plan on experimenting with different displacements to see if they can reduce the size, and therefore overall weight, in an attempt to make the new engine even more appealing.

The innovative design uses 3 different cylinders to produce power, but only two of these actually fire. The outside cylinders go through the normal procedure of intake, compression, combustion and exhaust to make their power. The cylinder located in the center however, receives the exhaust gas from one of the outside cylinders and allows it to expand even more, creating power.

The outside cylinders alternate to keep pressure even across the board. The result of this additional step is a torque curve similar to a diesel while still being able to ignite from a spark plug and without the emissions associated with diesel fuel.

Even without the reduction in size, Ilmor engineers are estimating a final output of around 150 horsepower but the time they are finished tweaking. Considering most engines of the same output are nearly 3 times as large as the new five stroke, it's safe to say this could change the future of automobiles.

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