Driven by energy conservation and environment protection, modern SI engines are required to have higher and higher power density. Consequently, engines and engine components are becoming tighter and lighter, and engines are more often operated at elevated speed and component temperature. Piston and piston ring designs thus face constant challenge to provide proper control of blow-by, oil consumption, friction, wear, and oil consumption. This paper is intended to give an overview of the problems associated with top ring performance in modern SI engines, the mechanisms behind these problems, and possible solutions. The analysis is based on engine test data and computer models. Major topics covered in this paper include (1) top ring flutter and collapse, and their influence on blow-by; (2) top ring reverse flutter and its influence on oil consumption; (3) contact between top ring and its groove, and its potential influence on ring/groove wear and micro-welding; (4) top ring/liner lubrication and its influence on ring face friction, wear, and scuffing.

Issue Section:
Power
Keywords:
internal combustion engines, performance evaluation, mechanical engineering, design for manufacture
Topics:
Collapse, Design, Engines, Flutter (Aerodynamics), Lubrication, Pistons, Pressure, Spark-ignition engine, Stress, Friction, Gas flow, Wear
1.
Nakada, M., 1993, “Piston and Piston Ring Tribology and Fuel Economy,” Proceedings of International Tribology Conference, Yokohama.
2.
Hill, S. H., and Sytsma, S. J., 1991, “A Systems Approach to Oil Consumption,” SAE paper 910743.
3.
Dr.-Ing. Hartmut Kamp et al., “Piston Technology for Passenger-Car Gasoline Engines, Lightweight Design—Microwelding—Direct Fuel Injection,” Kolbenschmidt—Competence in Engines.
4.
Dr.-Ing. Eduard Koeler, 1995, “Aluminum Engine Blocks,” Kolbenschmidt special print for IAA.
5.
Hoshino, K., et al., 1998, “Fuel Efficiency of SAE 5W-20 Friction Modified Gasoline Engine Oil,” SAE paper 982506.
6.
Cheng et al., 1993, “An Overview of Hydrocarbon Emissions Mechanisms in Spark-Ignition Engines,” SAE paper 932708.
7.
Tian
,
T.
,
Noordzij
,
L. B.
,
Wong
,
V. W.
, and
Heywood
,
J. B.
,
1998
, “
Modeling Piston-Ring Dynamics, Blow-by, and Ring-Twist Effects
,”
ASME J. Eng. Gas Turbines Power
,
120
, pp.
843
–
854
.
8.
Tian, T., 1997, “Modeling the Performance of Piston Ring-Pack in IC Engines,” Ph.D. thesis, MIT, Cambridge, MA.
9.
Tian, T., Rabute, R., Wong, V. W., and Heywood, J. B., 1997, “Effects of Piston-Ring Dynamics on Ring/Groove Wear and Oil Consumption in a Diesel Engine,” SAE paper 970835.
10.
Thirouard, B., Tian T., Hart, D. P., 1998, “Investigation of Oil Transport Mechanisms in the Piston Ring Pack of a Single Cylinder Diesel Engine, Using Two Dimensional Laser Induced Fluorescence,” SAE paper 982658.
11.
Min, B., et al., 1998, “Dynamic Characteristics of Oil Consumption—Relationship between the Instantaneous Oil Consumption and the Location of Piston Ring Gap,” SAE paper 982442.
12.
Shannon, I., and Wakem, M. P., 1999, “Lubricants Matter,” Engine Technology International issue 1/99.
13.
Tian, T., Wong, V. W., and Heywood, J. B., 1996, “A Piston Ring-Pack Film Thickness and Friction Model for Multigrade Oils and Rough Surfaces,” SAE paper 962032.
14.
Lebeck, A. O., 1991, “Principles and Design of Mechanical Face Seals,” John Wiley and Sons, New York.
15.
Shuster M., et al., 1996, “Piston Ring Microwelding Phenomenon and Methods of Prevention,” SAE paper 960745.
Copyright © 2001
 by ASME
You do not currently have access to this content.