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Compression Ratio Effects With Lean Mixtures
ISSN: 0148-7191, e-ISSN: 2688-3627
Published February 01, 1977 by SAE International in United States
Annotation ability available
To investigate the fuel-economy benefits of increased compression ratio in modern emission-controlled engines, the compression ratios of two car makes were increased one unit while holding emission levels and performance nearly constant. All cars were modified for lean-burn operation by using the Turbulent Flow Manifold, a carburetor adjusted for lean air-fuel mixtures, and special calibration of ignition timing and exhaust gas recycle rate. Exhaust port liners and a deceleration valve were used to control the tendency for HC emissions to increase at higher compression ratios.
In addition, thermal reactors were installed on one high-compression car. The increased efficiency of this aftertreatment device allowed a simultaneous improvement in fuel economy and decrease in hydrocarbon emissions. Based on fuel economy gains and refining savings, this car offers an 8.2% fuel savings over its 1977 certification counterpart.
CitationMarsee, F., Olree, R., and Adams, W., "Compression Ratio Effects With Lean Mixtures," SAE Technical Paper 770640, 1977, https://doi.org/10.4271/770640.
- Baker, R.E. Daby, E.E. Pratt, J.W. “Selecting Compression Ratio for Optimum Fuel Economy With Emission Constraints” SAE Paper 770191 Detroit February 28 March 4 1977
- Gumbleton, J.J. Niepoth, G.W. Currie, J.H. “Effect of Energy and Emission Constraints on Compression Ratio” SAE Paper 760826 Dearborn, Michigan October 18-22 1976
- “50,000-Mile Tests of Emissions and Durability of the Ethyl Lead-Tolerant Low-Emission System” ERM 75-2 Ethyl Corporation Research Laboratories Ferndale, Michigan December 1975
- Adams, W.E. Marsee, F.J. Olree, R.M. Hamilton, J.C. “Emissions, Fuel Economy, and Durability of Lean Burn Systems” SAE Paper 760227 Detroit February 23-27 1976
- Adams, W.E. Marsee, F.J. Lenane, D.L. “Lead-Compatible Emission Controls - A Route to Improved Fuel Economy” NPRA Paper F&L-74-60 Houston November 7-8 1974
- Federal Register 38 124 June 28 1973
- Federal Register 39 200 October 15 1974
- Air Conservation Note 73-3 Ethyl Corporation October 1973
- Cantwell E. N. “Octane Quality and Fuel Consumption with Emission Constraints.” Energy Conservation and Exhaust Gas Filter Developments Seminar conducted by Petroleum Institute Environmental Conservation Executive Division of the Australian Institute of Petroleum, Ltd. Melbourne, Australia April 28 1977
- Cantwell E. N. Bettoney W. E. Pierrard J. M. “A Total Vehicle Emissions Control System.” Paper No. 17-73 API Division of Refining Meeting Philadelphia, PA May 15 1973
- Cantwell E. N. Blenk M. H. Stuckey R. A. Russell H. J. “Demographic and Engineering Factors Affecting Gasoline Utilization.” Preprint No. 17-76 American Petroleum Institute Division of Refining Meeting Los Angeles, CA May 12 1976