The NEVIS (New Exhaust Valve & Intake System) engine is an innovative Internal Combustion Engine (ICE) that within a single patented engine design is estimated to nearly double the fuel efficiency attained by conventional ICE technologies. Additionally, its modular cylinder construction (e.g. 2, 4, 6 or 8 cylinder engines from a one-cylinder block) offers opportunities to enhance manufacturing efficiency while allowing a single facility to produce a wide range of engine sizes for varying power needs suited for diverse applications (automotive, aeronautic and marine). Its versatile design means it can be configured to be fuelled not only by gasoline but also by diesel, hydrogen and bio-fuels.
The history of the NEVIS Engine begins
with Cesare Bortone (45) and his interest in improving an engine performance.
A self-taught engineer,
This first stage of the NEVIS
project was carried out in cooperation with the University of Perugia with
over €400,000 in grant funding made available through the Italian Ministry of
Agriculture. The Ministry was interested in advancing engine technology for
agricultural applications and accepted the scope of the NEVIS project as
ultimately helpful in this regard. With the grant funding in place,
Following this phase and while
continuing to work in fields unrelated to engine development,
In 2001, Cesare Bortone began the
second phase of the NEVIS project based on the new engine patent entitled New
Exhaust Valve & Intake System (i.e. NEVIS). This
second phase focused on the development of a functional prototype based on
the NEVIS engine design and was funded, in part, by an Italian government
grant from MUIR (Ministry of
Education, University and Research). Grant
funding of approximately € 2.1 million was approved in 2002 and work began on
this 2nd phase of the NEVIS project in 2003 with
THINKING OUTSIDE-THE-BOX: THE “BORTONE CYCLE” AND THE NEVIS ENGINE
The thermodynamic cycle or rather the manner in which the internal combustion process takes place within most of today’s conventional ICEs dates back over 100 years: most automobiles either use the four-stroke spark ignition Otto cycle, conceptualized by the German engineer Nikolaus Otto in 1876, or the four-stroke compression ignition Diesel cycle invented by Rudolf Diesel and patented in 1892. The most efficient cycle for internal combustion is known as the Carnot cycle as studied by Nicolas Léonard Sadi Carnot in the 1820s. However, the problem with the Carnot cycle is that there is no engine available to make the theory of the cycle work.
While industry players have been seeking ways to improve the ICE for decades by making incremental improvements on the Otto and Diesel cycle engines, the time has come where the slow progress of improving the basic design invented over 100 years ago is no longer sufficient to address these issues. In fact, the industry as a whole is actively seeking to make progress on next generation technology such as hybrid ICE vehicles and fuel cell vehicles. The appearance of the first commercial hybrid automobiles (e.g. Toyota Prius and Ford Escape) along with significant investments being made in fuel cell technology is confirmation that incremental change is no longer sufficient.
NEVIS’S COMPETITIVE POSITION VERSUS NEXT GENERATION TECHNOLOGIES
The NEVIS engine design is believed to be sufficiently advanced to compete against hybrid powertrains within the automotive sector as these have largely been conceived in order to compensate for the ICEs poor performance across a range of partial power demands. This weakness of conventional ICEs is not present in the NEVIS engine and together with NEVIS’s other efficiency enhancements, performance is expected to exceed that of hybrids. This, together with the added costs of hybrids (projected to remain between 9 to 29% more expensive than a conventional port injection spark ignition ICE in 2010 ), provides comfort that the NEVIS engine represents an advance in efficiency capable of maintaining a long-term advantage. It is anticipated that the cost of a NEVIS-powered vehicle would approximate conventional ICE powertrains and could actually turn out to cost less, given its more simple and modular construction using traditional materials. Fuel cells represent another next generation technology that is very efficient in transforming energy into power. However, one must also examine the entire “Well-to-Wheel” process, that is from the source of the energy (e.g. an oil well) to the delivery of this energy to the vehicle and finally from the vehicle to the motion of the wheels. On this basis, according to an analysis by Toyota, its Hybrid Prius automobile has a Well-to-Wheel efficiency of 29% compared to 22% for a Fuel Cell vehicle powered by hydrogen made from natural gas. Furthermore, the retail cost of fuel cell vehicles is projected to remain between 50 to 105% more expensive than a conventional port injection spark ignition ICE in 2010.
A COMPARISON OF ENGINE SPECIFICATIONS
The horsepower data above marked as estimated is derived from research carried out by the University of Catania based on the specifications of the NEVIS prototype and an assumption of 2.000 rpms. However, as can be inferred from the table above, the NEVIS engine could run at nearly 3 times this level of rpms, yielding still more power – approximately 500HP, yet maintain an average piston speed (key to the life of an engine) similar to that of the BMW engine. Given that the specifications of the prototype were purposely conservative, other enhancements in terms of performance, size and weight are anticipated.
The two-cylinder prototype was put through a bench test with engine ignition for the first time in Lecce, Italy in early 2006 as part of the review process by MUIR (Ministry of Education, University and Research) for the government grants that funded the development of the prototype. This first test confirmed the correct functioning of the Bortone Cycle and the basic mechanical operation of the NEVIS engine. Preliminary testing without ignition also confirmed nearly 50% less friction/pumping resistance for an engine with a comparable displacement.
A further enhancement that is being considered which would have a major impact on emissions is adapting the NEVIS for HCCI -- Homogeneous Charge Compression Ignition. HCCI relies upon a very lean (high proportion of air to fuel) and well-mixed (Homogeneous) air-fuel mixture (Charge) that is compressed (Compression) until it autoignites (Ignition). The resulting spontaneous burn produces a flameless energy release in a large zone almost simultaneously -- very different than the spark/gasoline burn or the compression/diesel burn. The NEVIS engine adapted for HCCI would not only increase efficiency further but would also do away with NOx without the PM (particulate matter) emissions of a diesel.