This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Unthrottled Engine Operation with Variable Intake Valve Lift, Duration, and Timing
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 16, 2007 by SAE International in United States
Annotation ability available
The part-load fuel consumption potential of unthrottled engine operation using variable valve actuation is evaluated for a single-cylinder version of the GM 3.4 L DOHC engine. The investigation focuses on evaluating the practical range of the early-intake-valve closing (EIVC) variable valve actuation strategy, which includes intake-valve-opening positions ranging from 360 to 420 crank-angle degrees ATDC, intake-valve durations ranging from 54 to 226 crank-angle degrees, and peak intake-valve lifts ranging from 0.75 to 4.5 mm. In addition to the experimental investigation, a one-dimensional simulation evaluation is completed to examine the potential of enhanced in-cylinder charge motion when implementing variable-valve actuation.
A 7 % fuel consumption improvement is achieved for unthrottled engine operation when implementing the EIVC variable valve actuation strategy. This has been demonstrated at a part-load engine operating condition of 1300 rpm and 330 kPa net-mean-effective-pressure (NMEP) through the optimization of the intake-valve lift, duration, and timing while maintaining the conventional exhaust valve event. Along with this fuel consumption improvement, the engine-out HC emission level was 25 % higher and the engine-out NOx emission level was 25 % lower for unthrottled engine operation. Higher intake-valve velocities and in-cylinder charge motion could be achieved for unthrottled engine operation when using variable valve actuation; however, no significant combustion performance improvement was observed as a result of the enhanced charge motion.
CitationCleary, D. and Silvas, G., "Unthrottled Engine Operation with Variable Intake Valve Lift, Duration, and Timing," SAE Technical Paper 2007-01-1282, 2007, https://doi.org/10.4271/2007-01-1282.
- Nishimura, S., Fukuhara, T., and Teramoto, M., “Nissan V6 3.0 Litre, 4-Cam 24-Valve High Performance Engine,” SAE Transactions, Vol. 96, Section 4, pp. 303-316, 1987.
- Moriya Y., Watanabe A., Uda H., Kawamura H., Yoshiok M., “A Newly Developed Intelligent Variable Valve Timing System - Continuously Controlled Cam Phasing as Applied to a New 3 Liter Inline 6 Engine,” SAE Paper 960579, 1996.
- Stein, R. A., Galietti, K. M., and Leone, T. G., “Dual Equal VCT - A Variable Camshaft Timing Strategy for Improved Fuel Economy and Emissions”, SAE Paper 950975, 1996.
- “BMW Advances VVT Technology for New 100 hp-per”, WARD's Engine and Vehicle Technology Update,” pp. 4, August 15, 1995.
- Leone, T. G., Christenson, E. J. and Stein, R. A., “Comparison of Variable Camshaft Timing Strategies at Part Load,” SAE Paper 960584, 1996.
- Hosaka, T., and Hamazaki, M., “Development of the Variable Valve Timing and Lift (VTEC) Engine for the Honda NSX,” SAE Paper 910008, 1991.
- Matsuki, M., Nakano, K., Amemiya, T., Tanabe, Y., Shimizu, D., Ohmura, I., “Development of a Lean Burn Engine with a Variable Valve Timing Mechanism”, SAE Paper 960583, 1996.
- “Inside Honda's i-VTEC”, Engine Technology International, June 2001.
- Brustle, C. and Schwarzenthal, D., “VarioCam Plus - A Highlight of the Porsche 911 Turbo Engine,” SAE Paper 2001-01-0245.
- Flierl, R., and Kluting, M., “The Third Generation of Valvetrains - New Fully Variable Valvetrains for Throttle-Free Load Control,” SAE Paper 2000-01-1227.
- Tuttle, James, “Controlling Engine Load by Means of Late Intake-Valve Closing,” SAE Paper 800794.
- Tuttle, James, “Controlling Engine Load by Means of Early Intake-Valve Closing,” SAE Paper 820408.
- Urata Yasuhiro, Umiyama Hidezo, Shimizu Kiyoshi, Fujiyoshi Yoshihiro, Sono Hiroshi, and Fukur Koichi, “A Study of Vehicle Equipped with Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism”, SAE Paper 930820.
- Theobald, Mark, Lequesne, Bruno, and Henry, Rassem “Control of Engine Load via Electromagnetic Valve Actuators”, SAE Paper 940816.
- Flierl, R.; Gollasch, D.; Knecht, A.; Hannibal, W. “Improvements on to a Four Cylinder Gasoline Engine Through the Fully Variable Valve Lift and Timing System UniValve®” SAE Paper 2006-01-0223.
- Schechter Michael M. and Levin Michael B., “Camless Engine”, SAE Paper 960581.
- Pierik, Ronald and Gecim, Burak, “A Low-Friction Variable-Valve-Actuation Device, Part I: Mechanism Description and Friction Measurements”, SAE Paper 970338.
- Kreuter, Peter, and Heuser, Peter, “The Meta VVH System - A Continuously Variable Valve Timing System,” SAE Paper 980765.
- Eng. J. A., Leppard, W. R., Najt, P. M., Dryer, F. L., “Experimental Hydrocarbon Consumption Rate Correlations From a Spark Ignition Engine,” SAE Paper 972888, 1997.
- Alkidas, A. C., “Combustion Chamber Crevices: The Major Source of Engine-Out Hydrocarbon Emissions under Fully Warmed Conditions,” Prog In Energy and Comb Sci, Vol. 25, 1999.
- Urata, Y., Umiyama, H., Shimizu, K., Fujiyoshi, Y., Sono, H., and Fukuo, K., “A Study of Vehicle Equipped with Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism,” SAE Paper 930820.
- Sono, H., and Umiyama, H., “A Study of Combustion Stability on Non-Throttling S.I. Engine with Early Intake Valve Closing Mechanism,” SAE Paper 945009.