Engine Speed and Load on the Sealing Capacity of a Piston Ring-Pack


  •   Erjon Selmani

  •   Arian Bisha


The combustion chamber is ought to be perfectly sealed, however, part of the air and fuel mixture can escape from it. Among the several losses there is the gas flow from the inter-ring crevices, which is always present. This leakage is known as blow-by, and affects efficiency, correct lubrication and emissions. The amount of leakage is dependent on many factors, and among the most important are the engine speed and load, which are able to affect the system through the forces applied on it. The aim of this paper was to understand in a more detailed way how the engine speed and load could affect the sealing efficiency of a ring-pack. For this purpose, a complete range of speeds and loads were used in the simulations. The equations of the ring motions and gas dynamics has been implemented and solved in ©Ricardo RINGPAK solver. The results showed that inertia and inter-ring gas pressures drives the sealing behavior of the rings. The blow-by trend showed to decrease with the speed and increase with the load, exception made for the idle condition where the values were different to the other cases, especially at higher speeds. Among the two parameters, the engine speed resulted to affect more significantly the blow-by trend.

Keywords: Blow-By, Internal Combustion Engines, Speed, Load, Ring Dynamics


Zhao, Jia X., and F. Lee Chia-fon. Modeling of blow-by in a small-bore high-speed direct-injection optically accessible diesel engine. No. 2006-01-0649. SAE Technical Paper, 2006.

Froelund, Kent, and Ertan Yilmaz. "Impact of engine oil consumption on particulate emissions." ICAT International Conference on Automotive Technology, Istanbul, Turkey. 2004.

Green, R. M. and Cloutman, L. D., “Planar LIF Observations of Unburned Fuel Escaping the Upper Ring-Land Crevice in an SI Engine”, SAE paper 970823,1997

Alkidas, A. C. "Combustion-chamber crevices: the major source of engine-out hydrocarbon emissions under fully warmed conditions." Progress in energy and combustion science 25.3 (1999): 253-273.

Arnault, Nicolas, and Samuel Bonne. Engine Lube-Oil Consumption Stakes and Benefits from Significant Blow-by Oil Mist Reduction. No. 2012-01-1617. SAE Technical Paper, 2012.

Furuhama, Shoichi, and T. A. D. A. Tosio. "On the flow of gas through the piston-rings: 2nd Report, The character of gas leakage." Bulletin of JSME 4.16 (1961): 691-698.

Namazian, M., and John B. Heywood. Flow in the piston-cylinder-ring crevices of a spark-ignition engine: effect on hydrocarbon emissions, efficiency and power. No. 820088. SAE Technical Paper, 1982.

Keribar, Rifat, Zafer Dursunkaya, and Michael F. Flemming. "An integrated model of ring pack performance." ASME, Transactions, Journal of Engineering for Gas Turbines and Power 113 (1991): 382-389.

Wannatong, Krisada, Somchai Chanchaona, and Surachai Sanitjai. "Simulation algorithm for piston ring dynamics." Simulation Modelling Practice and Theory 16.1 (2008): 127-146.

Iijima, Naoki, et al. An experimental study on phenomena of piston ring collapse. No. 2002-01-0483. SAE Technical Paper, 2002.

Tian, T. "Dynamic behaviours of piston rings and their practical impact. Part 1: ring flutter and ring collapse and their effects on gas flow and oil transport." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 216.4 (2002): 209-228.

Tian, T. I. A. N. "Dynamic behaviours of piston rings and their practical impact. Part 2: oil transport, friction and wear of ring/liner interface and the effects of piston and ring dynamics." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 216.4 (2002): 229-248.

Rabute, Remi, and T. I. A. N. Tian. "Challenges involved in piston top ring designs for modern SI engines” Transactions-American Society of Mechanical Engineers Journal of Engineering for Gas Turbines and Power, 123.2 (2001): 448-459.

Cheng, Chao, Harold Schock, and Dan Richardson. "The Dynamics of Second Ring Flutter and Collapse in Modern Diesel Engines." Journal of Engineering for Gas Turbines and Power 137.11 (2015): 111504.

Delprete, Cristiana, Erjon Selmani, and Arian Bisha. "Gas escape to crankcase: impact of system parameters on sealing behavior of a piston cylinder ring pack." International Journal of Energy and Environmental Engineering (2019): 1-14

Selmani, Erjon, Cristiana Delprete, and Arian Bisha. "Simulation of the cylinder bore distortion and effect on the sealing capacity of the ringpack." SN Applied Sciences 1.4 (2019): 314.

Erjon Selmani. "The geometrical parameters of a piston-ringpack assembly and their impact on the blow by gasses. Fifth International Conference on “SOCIAL AND NATURAL SCIENCES – GLOBAL CHALLENGE 2019” (ICSNS V-2019), Vienna 13 April 2019. ISBN: 978-9928-259-15-8.

Curtis, John M. Piston ring dynamics and its influence on the power cylinder performance. No. 810935. SAE Technical Paper, 1981.

Kim, Changgi, Choongsik Bae, and Sangmin Choi. Gas flows through the inter-ring crevice and their influence on UHC emissions. No. 1999-01-1533. SAE Technical Paper, 1999.

Tamminen, Jaana, Carl-Erik Sandström, and Hannu Nurmi. Influence of the piston inter-ring pressure on the ring pack behoviour in a medium speed diesel engine. No. 2005-01-3847. SAE Technical Paper, 2005.

Zottin, Walter, Marcos Clemente, and Carmo Ribeiro. Application of a piston ring dynamics simulation code to solve blow-by fluctuation of a heavy-duty diesel engine in transient load operation. No. 942392. SAE Technical Paper, 1994.

Irimescu, Adrian, et al. "Compression ratio and blow-by rates estimation based on motored pressure trace analysis for an optical spark ignition engine." Applied Thermal Engineering 61.2 (2013): 101-109.

Aghdam, E. Abdi, and M. M. Kabir. "Validation of a blowby model using experimental results in motoring condition with the change of compression ratio and engine speed." Experimental thermal and fluid science 34.2 (2010): 197-209.

Dursunkaya, Zafer, Rifat Keribar, and Dana E. Richardson. Experimental and numerical investigation of inter-ring gas No. 930792. SAE Technical Paper, 1993.


Download data is not yet available.


How to Cite
Selmani, E. and Bisha, A. 2020. Engine Speed and Load on the Sealing Capacity of a Piston Ring-Pack: A Theoretical Analysis and Comparison with Literature. European Journal of Engineering and Technology Research. 5, 3 (Mar. 2020), 304–313. DOI:https://doi.org/10.24018/ejeng.2020.5.3.1775.