A newly emerging method of improving gas mileage and emissions from spark ignition engines is by computer control of the operation of the engine intake and exhaust valves. By controlling valve timing and duration the elimination of the throttle, a source of pumping loses can be minimized. One system is now in production by BMW, which uses a mechanism that varies the rocker arm ratio to vary the intake valve’s lift. As part of two Senior Design Projects a spark ignition internal combustion engine was modified at Minnesota State University, Mankato, to allow computer control of the engine’s valves. These projects worked at replacing the mechanically operated intake and exhaust valves with pneumatically operated valves controlled by computer in the form of a Programmable Logic Controller. The valves controlled by the solenoids switched compressed air to pneumatic cylinders that operate the existing poppet intake and exhaust valves on the engine. This paper will present the background, operational issues, and the initial results of the project.

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