June 2009- SAE International's 2009 World Congress, held April 20-23, was notable on several fronts. First, compared with last year, there were fewer companies displaying their products or services likely due to the economy. Second, there were more companies from China, South Korea and Mexico with displays. Third, there were several unique products.

One was a hydraulic hybrid truck that offered some characteristics different from regular hybrids. According to the Environmental Protection Agency, hydraulic hybrid technology vehicles use a hydraulic energy storage and propulsion system that captures and stores a large amount of the energy normally wasted in vehicle braking. It then uses this to help propel the vehicle during acceleration.

For vehicles that do a lot of stop-and-go driving, these hydraulic/hybrid drivetrains are particularly attractive. The hydraulic system captures and uses a large percentage of the energy normally lost through braking by recovering it. When a vehicle brakes, it will pump hydraulic fluid into a reservoir under high pressure. Then when accelerating, this high-pressure hydraulic fluid will be released, helping propel the vehicle and increase acceleration performance, along with fuel economy and engine efficiency.

Using hydraulics for propulsion is nothing new. But combining it with an engine that does most of the work and hydraulics that offer a boost when accelerating and braking can benefit both emissions and overall fuel economy.

Engine prototype introduced
Also at the show, there was an unveiling of a new engine concept called the Scuderi engine.

The Scuderi Groupintroduced a cutaway model of its first proof-of-concept prototype for its Scuderi split-cycle engine, described as a more fuel-efficient, more powerful and greener technology for internal combustion engines.

The engine cutaway is an exact duplicate of the proof-of-concept prototype undergoing testing and analysis by an independent laboratory in San Antonio. According to a news release from the company introducing the engine at the SAE show, "The 1-liter, naturally aspirated gasoline prototype is expected to produce up to 80 percent fewer toxins than a typical internal combustion engine. When fully developed with its turbocharged and air-hybrid components, the engine is expected to achieve significant gains in fuel efficiency. The original Scuderi engine was designed and invented by Carmelo Scuderi (1925-2002).

"It uses a split-cycle design that divides the four strokes of a conventional combustion cycle over two paired cylinders: one intake/compression cylinder and one power/exhaust cylinder. By firing after top-dead center, it produces highly efficient, cleaner combustion with one cylinder and compressed air in the other. Unlike conventional engines that require two crankshaft revolutions to complete a single combustion cycle, the Scuderi Engine requires just one."

Besides the improvements in efficiency and emissions, the company says studies show the engine is capable of producing more torque than conventional gasoline as well as diesel engines.

"Scuderi split-cycle technology is significant because it gives automotive OEMs an immediate solution for complying with higher emissions and efficiency standards going into effect around the world, without having to make large investments to modify current production processes," the company stated. "The Scuderi Group expects further advancement of the technology once the engineering community begins working with the engine, making their own modifications that will most likely take the efficiency to even higher levels." In many respects, though, this engine seems to mimic a supercharged two-cycle engine that uses a piston as an air charger, pumping air into an adjacent cylinder that fires on every cycle. But the compression ratio is much higher, and the company says there are no problems with engine knock. Also, Scuderi says emissions are much lower than a conventional engine. Auto companies, however, aren't receptive to having engines built by vendors for which they would have to pay royalties to use. FFJ