Throughout the history of the internal combustion engine there have been a multitude of scientists, inventors and entrepreneurs shouting claims about revolutionary new engine designs promising greater efficiency, more power, fewer emissions and lower production and running costs.
However, to this day we are yet to see anything come up to replace the existing four-stroke engine design currently found in most cars (not including the newer generation of hybrids and all-electrics). Most of these ‘alternative’ designs usually vanish as quickly as they appear but one company, America’s own EcoMotors International, has gained the spotlight following the announcement it has received $23.5 million in funding from Microsoft founder Bill Gates and investor Vinod Khosla.
The funding is to be used to further develop a new engine design called the Opposed Piston Opposed Cylinder, or OPOC for short. According to EcoMotors, based in suburban Detroit, the new OPOC engines feature 50 percent fewer parts than regular engines, while also being 50 percent more fuel efficient. Everyone knows that a lot of energy in internal combustion engines is wasted due to frictional losses, and having 50 percent fewer parts should go a long way to remedying this issue.
But that’s only part of the story--the OPOC engine also features a two-stroke design. The benefit here is that a two-stroke engine delivers a power pulse with every revolution of the crankshaft, as opposed to the four-stroke engine which fires each cylinder on every other revolution.
Previous two-stroke designs were quickly banished as emissions standards started to get tougher. The design is such that unburned fuel and lubricating oils are released through the exhaust, causing emissions to be much higher. However, EcoMotors believes its design has overcome this challenge.
Its engine also generates one power stroke per crank revolution per cylinder. It comprises two opposing cylinders per module, with a crankshaft between them, and each cylinder has two pistons moving in opposite directions. This innovative design configuration eliminates the cylinder-head and valve-train components of conventional engines, offering an efficient, compact and simple core engine structure. The design also allows for multiple modules to be linked for more powerful applications.
The company is now working on the sixth generation of the OPOC engine design and eventually hopes to see it commercialized for use in cars, light trucks, commercial vehicles, aerospace, marine, agriculture, auxiliary power units, generators, etc.--essentially, anywhere conventional gas or diesel power is currently utilized.
Interestingly, the OPOC engine design was conceived by Peter Hofbauer, the former Volkswagen powertrain engineer that designed the German automaker’s first high speed diesel engine. Additionally, EcoMotors’ CEO, Don Runkle, is a former employee of General Motors and one of the key men behind the EV1 all-electric car.
[EcoMotors]
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By Bob Brooks Posted: 7/13/2010 7:20am PDT
By Béranger Posted: 7/13/2010 11:34pm PDT
http://en.wikipedia.org/wiki/Opposed-piston_engine
By Robin Posted: 7/14/2010 3:18am PDT
By James Posted: 7/14/2010 12:23pm PDT
How are they planning on improving the emissions, efficiency and power density of this two stroke? Two strokes have a lot of problems in larger engines... there is no conspiracy as to why most engines over 10hp are based on the four stroke principle. The reasons are based on sound engineering.
By paintball barrel Posted: 7/14/2010 9:54pm PDT
By paintball barrel Posted: 7/14/2010 9:57pm PDT
So ecomotors, detach your silly upper pistons from the crank, and put them on a servo actuated cam instead. Bam. variable CR. Now we're getting closer to something that doesnt suck.
By anthony Posted: 7/15/2010 6:45am PDT
By anthony Posted: 7/15/2010 7:13am PDT
By hortonhcci Posted: 7/15/2010 5:55pm PDT
By Chris Posted: 7/20/2010 6:57pm PDT
There appears to be considerable misunderstanding regarding the opposed piston design in the OPOC configuration. The inside and outside pistons are arranged with a slightly asymmetrical timing, so that the exhaust and intake ports are never open simultaneously. The design is also perfectly balanced, and all of the forces on the crankshaft cancel, aside from the rotation. (In the past, they made a point of balancing a golf ball on a running engine.) The longer connecting rods are only under tension, and the shorter, only under compression. As such, the bearings and connecting rods may all be light weight, and the pistons need only travel half the distance.
Anyway, a surprising and welcome investment by Mr. Gates.
By Manousos Pattakos Posted: 7/22/2010 8:19pm PDT
the pattakon OPRE (another opposed piston engine) is:
more compact,
simpler,
cheaper,
has built-in scavenging pump,
has wider rev-range,
provides more time to the fuel to get prepared and burned in-time,
is better balanced,
is more fuel efficient.
For more details (and videos of the working prototypes) http://www.pattakon.com/pattakonOPRE.htm
By dlen Posted: 9/7/2010 12:10pm PDT
High efficiency means high power density - and this is a reliability problem for any engine, be it 4- or 2-stroke. But high mileage needs high power density, because thermodynamic and conduction losses are lower. So it is very much a material science problem.
The OPOC-concept of using 2 independent units clutched together if high power is needed is very smart and boosts efficiency in low power regime. But of course this would be possible with 4-stroke too.
By Koz Posted: 2/14/2011 6:23am PST
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