This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Instantaneous Crank Speed Variations as Related to Engine Starting
Annotation ability available
Sector:
Language:
English
Abstract
Typically, engines with relatively few cylinders have required higher cranking speed to start in low temperature ambients. Of the several factors that contribute to cold startability, this study has focused on the instantaneous speed variation of the engine during cranking. This theoretical computer study revealed that engines slow substantially during compression and that the lengthening of compression time is exaggerated as the number of cylinders is reduced. It is hypothesized that long compression time creates excessive heat and blowby losses. In turn these produce low compression temperatures and pressures, hence greater difficulty in igniting the charge especially under cold cranking conditions were average engine speed is low, By matching the compression times of various engines designs, the relative average speeds required to start can be predicted with reasonable accuracy.
Recommended Content
Authors
Citation
Poublon, M., Patterson, D., and Boerma, M., "Instantaneous Crank Speed Variations as Related to Engine Starting," SAE Technical Paper 850482, 1985, https://doi.org/10.4271/850482.Also In
References
- Patterson, D. J. “ Engine Torque and Balance Characteristics,” SAE Paper No: 821575 SP 532 51 57
- Hutcheon K. F. Marks, R. L. “ Developments in Starter Motor Application to Diesel Engines ,” IME Proc. 1969-70 184 3A 97 102
- Austin, A. E. W. Lyn, W. T. “ Some Investigations of Cold Starting Phenomena in Diesel Engines ,” IME Paper Automobile Division Dec. 8 1959
- Meyer, W. E. De Carolis, J. J. “ Compression Temperatures in Diesel Engines Under Starting Conditions ,” SAE Trans. 1962 163 174