This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Cold engine cranking torque requirement analysis
Technical Paper
2007-01-1967
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
This paper presents an analytical approach of estimating the minimum torque to start an engine at low temperature down to -30 °C. Obviously, the output torque from a starter motor has to overcome the conventional mechanical friction torque from piston, bearings, valvetrain and auxiliaries, and gas torque from the cylinder pressure/vacuum rise due to piston motion. Using the mechanical friction models developed previously by the author, the paper shows that although piston, bearings and valvetrain are still significant mechanical friction sources for a cold engine, the gas torque is actually the biggest contributor to the minimum required turning torque. The analysis also showed that the gas resistance torque was sensitive to the crankshaft position at the start. For example, for a V8 gasoline engine, the gas resistance torque is the highest if the engine starts at the intake valve close (IVC) position.
Recommended Content
Authors
Citation
Zhou, Q. and Houldcroft, J., "Cold engine cranking torque requirement analysis," SAE Technical Paper 2007-01-1967, 2007, https://doi.org/10.4271/2007-01-1967.Also In
References
- Tomai, G. et al “Saturn engine stop-start system with an automatic transmission” SAE 2001-01-0326
- Fattic, G.T. et al “Cold starting performance of a 42-volt integrated starter generator system” SAE 2002-01-0523
- Leonardi, F. Lawson, G. “Cold-cranking test for V6 engines for ISG applications” Ford Technical Report, SRR-2001-0278 Nov 2001
- Shayler, P.J. et al “Contribution to engine friction during cold, low speed running and the dependence on oil viscosity” SAE 2005-01-1654
- Patton, K.J. et al “Development and evaluation of a friction model for spark ignition engines” SAE 890836
- Zhou, Q. Richardson, S. “Piston ring pack tribological analysis of Jaguar AJ27 4.0L V8 engine” Topics in Engine Lubrication and Engine Controls 3 Procs. of the 2000 ASME fall technical conference 1 13
- Zhou, Q. et al “Prediction of total engine friction power loss from detailed component models” Tribology Series 41 Dowson et al 2003 761 766
- Patir, N. Cheng, H. S. “An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication” Trans. ASME 100 1976 12 17
- Christensen, H. “A theory of mixed lubrication model” Procs. I. Mech. E. 186 1972
- Zhou, Q. “The development of the piston ring pack evaluation system” 19 th CIMAC Florence, Italy 1991
- Zhou, Q. Richardson, S.H. “Friction prediction of a cam/tappet interface using a EHL model with consideration of surface texture” Tribology Series 40 Dowson et al 2002 539 545
- Dyson, A. “Elatohydrodynamic lubrication and wear of cams bearing against cylindrical tappets” SAE 770018
- Booker, J. “Design of dynamically loaded journal bearings” Fundamental of the design of fluid film bearings Rohde, S.M. et al ASME 1979 31 44