Humphreys Constant - Compression Engine 520231

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:
  1. 1.
    At light loads the compression ratio is at a maximum, providing best thermal efficiency and therefore lowest fuel consumption.
  2. 2.
    At intermediate loads the compression ratio is somewhat lower but still high enough to provide good thermal efficiency and therefore low fuel consumption.
  3. 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.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.