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In this investigation, recently developed techniques to locate knock origins were applied to study fuel and deposit effects as they interact with charge motion. Particularly, the individual and interactive effects of swirl, fuel composition, localized heating, and deposits on in-cylinder knock origin were studied. A Waukesha Split Head CFR engine was modified to accept four pressure transducers for calculating by triangulation the cycle resolved in-cylinder origin of engine knock. Location of the origin of knock within the combustion chamber was based on the difference in time for each pressure transducer to register the onset of knock during the combustion cycle. Computer software was developed and optimized to maximize the success rate in locating knock within 1 cm. In order to explore the difference in location of knock due to fluid dynamics within the cylinder, the shrouded intake valve of the engine was modified to create different swirl conditions within the combustion chamber.

To reduce the time associated with fuel additive testing, a quick, reliable and repeatable screening test was necessary for the evaluation of intake system deposit levels. The additive development process has also shown certain additive packages to result in intake valve stickiness at low temperatures. A successful additive screening procedure was developed using a portable generator set. This paper describes an 80 hour test in which different additives and dosage levels can be evaluated for both intake valve deposit and stickiness levels. Test results were comparable to those found in automobile testing.