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Innovative Valve Lifter For Increasing Diesel Fuel Economy Demonstrated For U.S. Navy
Low cost lifter retrofit technology projected to improve Diesel fuel economy by 5% or more when rebuilding truck, generator, and other engines.
The U.S. Navy is attempting to improve the fuel economy of Diesel engines already in service. A promising path is to lower compression ratio for reduced friction, but this is limited by cold weather starting issues. To counter this, Smart Lifter provides a higher effective compression ratio during cold starting. This is accomplished by partial collapse of the intake valve lifter causing the valve to close near bottom center. The result is full design compression ratio under starting conditions, thus allowing a lower overall engine compression ratio for normal operation. Compression ratio reduction is accomplished by piston replacement when the engine is rebuilt. Once the engine is running, the lifter is locked to provide normal intake valve operation indicated by the camshaft at the lower compression ratio.
When applied to the exhaust valve lifter, the Smart Lifter provides early closing of the exhaust valve during cold cranking, thus permitting evaporated and finely divided fuel droplets to remain in the cylinder. This aids cold starting further.
Applied to both intake and exhaust lifters, the Smart Lifter design allows a significant reduction of engine compression ratio with attendant improvements in fuel economy and combustion noise. “This low cost technology can provide fuel economy and emission benefits for new engine designs as well”, said Dr. Donald Patterson, President of Electro-Mechanical Associates. “It provides another tool for engine manufacturers to meet future EPA, DOT, and CARB emission and fuel economy requirements.”
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About Electro-Mechanical Associates, Inc.
Electro-Mechanical Associates is a Michigan based engine systems engineering organization which developed out of the University of Michigan Automotive Laboratory in 1988. Key personnel are: Dr. Donald J. Patterson, Mr. Kevin M. Morrison and Mr. George B. Schwartz with combined engine engineering experience of more than 100 years. Significant recent design programs have been spark-ignition engine variable compression ratio and electro-magnetic valves. Electro-