
5 Engine cooling and vehicle heating
5.1 HEAT TRANSFER AND COOLING MEDIA
The need for engine cooling
From the viewpoint of converting heat into mechanical
energy, it follows that if each piston accomplished its
power stroke starting at the temperature of combustion,
such an engine would in theory be highly efficient. To
achieve this in practice, however, would entail unac-
ceptably high operating temperatures with adverse
effects on both engine lubrication and materials.
Excessively high operating temperatures would cause
breakdown of the lubricating oil films, resulting in
undue wearing and possible seizure of the working
parts.
The behaviou ...