This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Indicated Cycle Efficiency Improvements of a 4-Stroke, High Compression Ratio, S.I., Opposed-Piston, Sleeve-Valve Engine Using Highly Delayed Spark Timing for Knock Mitigation
Technical Paper
2012-01-0378
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
A fixed-geometry configuration of Pinnacle Engines' 4-stroke spark-ignited 250cc single-cylinder opposed-piston reciprocating sleeve-valve engine is presented. A test cell has been developed with a custom crank-angle based data acquisition system to allow friction testing and indicated cycle development. Incipient knock criteria are defined and test results are presented to compare the opposed-piston's indicated cycle performance to conventional single-cylinder engines. At high loads, the Pinnacle opposed-piston engine utilizes the Cleeves cycle, an operating mode in which spark timing is highly delayed from best power spark advance, to enable knock-free operation at an elevated 15:1 compression ratio using 87 octane fuel. Data is presented for sleeve-valve operating temperatures, peak cylinder pressure effects, and exhaust gas temperatures. LogP-logV plots at key drive-cycle operating conditions highlight indicated cycle advantages of the opposed-piston sleeve-valve engine over two configurations of a comparison poppet-valve engine. Data is presented to show that extended lean operating limits enable reduced drive-cycle emissions in the target vehicle. Indicated cycle performance using gaseous CNG/methane is also presented. The engine has been developed such that, with the most basic configuration, light-load indicated efficiency improvements of 15-30% can be realized over conventional poppet-valve technology.
Recommended Content
Authors
Topic
Citation
Willcox, M., Cleeves, J., Jackson, S., Hawkes, M. et al., "Indicated Cycle Efficiency Improvements of a 4-Stroke, High Compression Ratio, S.I., Opposed-Piston, Sleeve-Valve Engine Using Highly Delayed Spark Timing for Knock Mitigation," SAE Technical Paper 2012-01-0378, 2012, https://doi.org/10.4271/2012-01-0378.Also In
References
- Cavina, N. Corti, E. Minelli, G. Moro, D. et al. “Knock Indexes Normalization Methodologies,” SAE Technical Paper 2006-01-2998 2006 10.4271/2006-01-2998
- Mittal, V. Revier, B. Heywood, J. “Phenomena that Determine Knock Onset in Spark-Ignition Engines,” SAE Technical Paper 2007-01-0007 2007 10.4271/2007-01-0007
- Millo, F. Ferraro, C. “Knock in S.I. Engines: A Comparison between Different Techniques for Detection and Control,” SAE Technical Paper 982477 1998 10.4271/982477
- Chun, K. Heywood, J. “Characterization of Knock in a Spark-Ignition Engine,” SAE Technical Paper 890156 1989 10.4271/890156
- Sawamoto, K. Kawamura, Y. Kita, T. Matsushita, K. “Individual Cylinder Knock Control by Detecting Cylinder Pressure,” SAE Technical Paper 871911 1987 10.4271/871911
- Heywood, John B. “Internal Combustion Engine Fundamentals,” McGraw-Hill, Inc. 0-07-100499-8 1988
- Taylor, Charles F. “The Internal-Combustion Engine in Theory and Practice,” Second 1 The M.I.T. Press 1985
- Lang, O. Geiger, J. Habermann, K. Wittler, M. “Boosting and Direct Injection -Synergies for Future Gasoline Engines,” SAE Technical Paper 2005-01-1144 2005 10.4271/2005-01-1144
- Basshuysen, Van “Gasoline Engine with Direct Injection,” GWV Fachverlage GmbH Wiesbaden 978-3-83480670-3 2009
- Russ, S. “A Review of the Effect of Engine Operating Conditions on Borderline Knock,” SAE Technical Paper 960497 1996 10.4271/960497
- Taylor, Charles F. “The Internal-Combustion Engine in Theory and Practice,” Second 2 The M.I.T. Press 1985