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Humphreys Constant - Compression Engine
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English
Abstract
THE Humphreys engine is a conventional powerplant to which has been added a device for automatically varying the clearance volume of the combustion chamber. This allows the compression ratio to be varied so that:
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1.
At light loads the compression ratio is at a maximum, providing best thermal efficiency and therefore lowest fuel consumption.
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2.
At intermediate loads the compression ratio is somewhat lower but still high enough to provide good thermal efficiency and therefore low fuel consumption.
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3.
At full load the compression ratio is at its lowest point, so that the engine is able to operate without knock with fuels of quite low octane number.